PLEASE HELP!!
Solve x^2=81 and x^2-18x=7.
Please show your work!

Answers

Answer 1

Answer:

x² = 81 , x = ± 9

x² - 18x = 7 : x = 9 ± √(22)

Step-by-step explanation:

x² = 81

simply take the square root of both sides

x = ± 9

x² - 18x = 7

This question is a bit more complicated as there is a variable with a power as well as a variable with no power. To solve for x we are going to have to put the equation in quadratic form then solve using the quadratic equation

x² - 18x = 7

put the equation in quadratic form by subtracting 7 from both sides so that the equation is equal to 0

x² - 18x - 7 = 0

we can now solve for x using the quadratic equation

recall the quadratic equation : [tex]x=\frac{-b+\sqrt{b^2-4ac} }{2a}[/tex]

where the value of a,b and c are derived from the equation

remember the equation is in quadratic form ax² + bx + c = 0

so ax² + bx + c = 0 : x² - 18x - 7 = 0

knowing this we can assign variables, a = 1 , b = -18 and c = -7

now we plug in the variables into the quadratic equation

recall equation : [tex]x=\frac{-b+\sqrt{b^2-4ac} }{2a}[/tex]

a = 1 , b = -18 and c = -7

plug in values

[tex]x=\frac{-(-18)+\sqrt{(-18)^2-4(1)(-7)} }{2(1)}[/tex]

remove parenthesis

[tex]x=\frac{18+\sqrt{(-18)^2-4(1)(-7)} }{2(1)}[/tex]

simplify exponent

[tex]x=\frac{18+\sqrt{324-4(1)(-7)} }{2(1)}[/tex]

simplify multiplication in square root and on denominator

[tex]x=\frac{18+\sqrt{324+28} }{2}[/tex]

simplify addition

[tex]x=\frac{18+\sqrt{352} }{2}[/tex]

simplify radical

[tex]x=\frac{18+4\sqrt{22} }{2}[/tex]

simplify fraction

[tex]x=9+or-\sqrt{22}[/tex]

and we are done!


Related Questions

Point JJ is located at (-4,5) on the coordinate plane. Point J is reflected over the x-axis to create point J′. What ordered pair describes the location of J'?

Answers

Answer: (-4, -5) in 3rd Quadrant

Step-by-step explanation: Reflection across x axis only flips the sign of y coordinate

Which statistical measure is not strongly affected by a few outliers in the data?.

Answers

Answer:  Median

The median is not affected by large or small outliers.

The mean on the other hand is affected by outliers. The more distant the outlier, the more skewed the mean will be.

For example, home prices will have a larger than normal mean because of very rich mansions which are far above the average group. This is why the median home price is a more useful measure of center.

8. Dimensions and Construction. The Space Needle is 605 feet (184m)
tall, the rough equivalent of 60 stories, though it only has a few
Moors. The outdoors observation deck, along with a cafe and
historical information can be found at 520 feet (158m). The
observation deck is circular, with a 138 foot (42m) diameter.
observation deck
a) What is the Circumference of the observation
deck? Use the formula C=21tr = d.
Round your answer to the nearest tenth.

Answers

Answer:

A

Step-by-step explanation:

it a because it there the right answer

Giselle made several apple and peach pies. She bought peaches for $4 per pound and apples for $2 per pound. If Giselle spent $60 to buy 24 pounds of fruit, how many pounds of peaches did she buy?

Answers

The number of pounds of peaches is 6 pounds and the number of pounds of apples is 18 pounds

Given:

cost of peaches per pound = $4

cost of apples per pound = $2

Total amount spent = $60

Total pounds bought = 24

let

x = number of peaches

y = number of apples

x + y = 24 (1)

4x + 2y = 60 (2)

multiply (1) by 2

2x + 2y = 48 (3)

4x + 2y = 60 (2)

subtract (3) from (2)

4x - 2x = 60 - 48

2x = 12

x = 12/2

x = 6

substitute x = 6 into (1)

x + y = 24 (1)

6 + y = 24

y = 24 - 6

y = 18

Therefore, the number of pounds of peaches is 6 pounds and the number of pounds of apples is 18 pounds

A poll worker analyzing the ages of voters found that mu = 65 and sigma = 5. what is a possible voter age that would give her zx = 1.14? round your answer to the nearest whole number. 59 66 71 90

Answers

A poll worker analyzing the ages of voters found that μ = 65 and σ = 5. The possible voter age that would give her zx = 1.14 is 71.

What do you mean by standard deviation?

In statistics, Standard deviation is a measure of the variation of a set of values.

σ = standard deviation of a population

N = number of observations of population

X = mean

μ = population mean

It is given that the random variable,

X = The ages of voters

μ = The analysis is having mean of 65

Standard deviation = 5

X = normal (65,5) Now, we will convert it into Z-score concept ,

Z = x - 65/ 5

z = 1.14

X = 65 + 5z

So, X = 65 + 5(1.14)

         = 65 + 5.7

         = 70.70

Therefore, We can also write it by rounding off the value,i.e.=71

The possible voter age that would give her zx = 1.14 is 71.

Learn more about standard deviation

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Answer:

C, 71

Step-by-step explanation:

quiz edge

ONLY ANSWER IF YOU KNOW THE ANSWER (15 POINTS HELP PLEASE)
CORRECT ANSWER WILL GET BRAINLEST AND LINKS WILL BE REPORTED
THANKS.
A number cube with six sides numbered 1 through 6 is rolled. The probability of rolling a 5 is 1/6.

What is the probability of not rolling a 5?

Enter your answer as a fraction, in simplest form, in the box.

Answers

Answer:

The probability of all events occurring is 1

(1/6)+p=1

p=1-1/6

p=5/6

The probability of not rolling 5 is 5/6

Or you could have just said there are five numbers other than 5 out of the six so:

5/6

For what value of c does the following system not have a solution.

1/2x+1/5y=2
5x+2y=c

Answers

Answer:

The answer is 3. 1. There is '0' point of intersection, that means they do not intersect. This only possible when the lined are parallel to each other.

'c' can be any real number except 4 for which the considered system would have no solution.

When does a system of linear equation have no solution?

When both the lines(represented by both the equations) are parallel and not coincident, then that system of linear equations have no solutions as there is no common point on both line.

If they are coincident (lying over each other), then there will have infinite solution since in that case, they will have infinite points in common.

Thus, if two lines are not in any of above case, they intersect at single point and in that case, the considered system of equation has unique single solution.

How to get the slope intercept form of a straight line equation?

If the slope of a line is m and the y-intercept is c, then the equation of that straight line is given as:

[tex]y = mx +c[/tex]

Parallel lines(non-coincident) have same slope but different y-intercept.

Converting these equations to slope-intercept form, we get:

For first line:

[tex]\dfrac{1}{2}x + \dfrac{1}{5}y = 2\\\\ \dfrac{1}{5}y = 2 - \dfrac{1}{2}x\\\\y = 10 - \dfrac{5}{2}x\\\\y = -\dfrac{5}{2}x + 2[/tex]

and

For second line:

[tex]5x + 2y = c\\\\y = \dfrac{1}{2}c - \dfrac{5}{2}x\\\\y = -\dfrac{5}{2}x + \dfrac{c}{2}[/tex]

For no-solution, we need both lines to stay parallel but not coincident so that there is no common point (solution of this system) between those two lines.

Thus, we get:

[tex]2 \neq \dfrac{c}{2}\\\\\text{Multiplying 2 on both the sides}\\\\c \neq 4[/tex]

Since 'y' assumes real numbers assumingly, so 'c' can be any real number except 4 for which the considered system would have no solution.

Below is image attached of those parallel lines when c = 10.

Thus,  'c' can be any real number except 4 for which the considered system would have no solution.

Learn more about the case of 'no solution' here:

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19. Select all the measures that are equivalent to 10 meters.

0. 01 kilometer

B)

1000 millimeters

100 millimeters

0 1000 centimeters

0. 1 kilometer

100 centimeters

Help I don’t know!

Answers

Answer:

10 meters is equivalent to 1000 cm and 0.01 kilometers

Step-by-step explanation:

What are the solutions to the equation y = 4x2 +5x−6?

Answers

Answer:

Option D: x = -2; x = 3/4

Step-by-step explanation:

Hello!

We can factor this expression and then find the zeroes to find our solutions.

Factor:

We have to factor by grouping. Multiply the 1st and last term, 4x² and -6 is -24x², and find two factors that equal to -24x² and add up to the second term, 5x. 8x and -3x work for this.

y = 4x² + 5x - 6y = 4x² + 8x - 3x - 6y = 4x(x + 2) - 3(x + 2)y = (4x - 3)(x + 2)

Zero-Product Property

Now, set the equation equal to zero.

0 = (4x - 3)(x + 2)

Remember, if two numbers, a and b, multiply to 0, either a or b or both numbers must be zero. So now we set both factors to zero, hence the zero-product property.

4x - 3 = 04x = 3x = 3/4

And the next one:

x + 2 = 0x = -2

The solutions are x = -2, and x = 3/4, or Option D

please help me asap! Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar. A multiple-choice question has five answer options of which two options are correct. What is the probability of randomly choosing the correct pair of answer options? The probability of choosing the correct pair of answer options is .

Answers

Using the combination formula, it is found that there is a 0.1 = 10%  probability of randomly choosing the correct pair of answer options

What is the combination formula?

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this problem, 2 answers are chosen from a set of 5, hence the total number of options is given by:

[tex]C_{5,2} = \frac{5!}{2!3!} = 10[/tex]

Only one pair is correct, hence the probability of randomly choosing the correct pair of answer options is given by:

p = 1/10 = 0.1 = 10%.

More can be learned about the combination formula at https://brainly.com/question/25821700

Enter an expression that shows the sum of exactly two terms that is equivalent to 6m + 3n + 8m + 5n

Answers

Answer: 14m+8n

Step-by-step explanation:

Simplify the expression

6m+3n+8m+5n

6m+8m+3n+5n

14m+8n

It is the same expression except that it is simplified and contains only 2 terms

If a person with an hourly pay of $9.50 per hour gets a 20% raise, what is the new hourly pay?

Answers

20% = .20

$9.50 • 1.20 (the one gives you the original $9.50 and the .20 is the 20%) = $11.40

The person’s new hourly pay is $11.40

What is the equation of the line passing through the point (2,3) and perpendicular to the line y = 2x+7​

Answers

Answer:

[tex]y =\dfrac{-1}{2}x +4[/tex]

Step-by-step explanation:

Equation of the line: y = mx +b

y = 2x + 7

m = 2

Slope of the perpendicular line = [tex]-\frac{1}{m}[/tex]

   [tex]\sf m_1 =\dfrac{-1}{2}[/tex]

Equation of the perpendicular line:

             [tex]y= \dfrac{-1}{2}x + b[/tex]

This line is passing throught (2 ,3). Substitute the x & y coordinate in the above equation and now we can obtain the value of b (y-intercept)

           [tex]\sf 3 = \dfrac{-1}{2}*2+b\\\\3 = -1 + b\\[/tex]

   3  +  1 = b

          4 = b

Equation:

      [tex]y =\dfrac{-1}{2}x +4[/tex]

Help me with this one too Have a good day

Answers

Answer:

So, a.0, b.1/10, c.81, d.1/64

Step-by-step explanation:

Part A, anything raised to the power of zero is equal to zero. So suppose we have a constant, b, and we raise it to the power of zero, so b^0, it'll always be 0.

Part B, a negative power essentially means that you'll have to inverse the number. Once again, if we have a constant, b, and we raise it to the power of -1, it'll end up being 1/b. So b^-1 = 1/b.

Part C, its simply just multiplying 3 with itself four times.

Part D, as mentioned before, anything raised to a negative power means that you need to inverse the number. So 4^-3 is equal to 1/4^3, meaning that its just 1/64.

Starting at its rightmost position, it takes 2 seconds for the pendulum of a grandfather clock to swing a horizontal distance of 18 inches from right to left and 2 seconds for the pendulum to swing back from left to right. which of the following equations models d, the horizontal distance in inches of the pendulum from the center as a function of time, t, in seconds? assume that right of center is a positive distance and left of center is a negative distance. d = 9 cosine (startfraction pi over 4 endfraction t) d = 9 cosine (startfraction pi over 2 endfraction t) d = 18 cosine (startfraction pi over 4 endfraction t) d = 18 cosine (startfraction pi over 2 endfraction t)

Answers

The expression that models d, the horizontal distance in inches of the pendulum from the center as a function of time, t, in seconds is d=9cosine[(π/2)t] option second is correct.

What is the frequency?

It is defined as the number of waves that crosses a fixed point in one second, known as frequency. The unit of frequency is per second.

The pendulum takes 2 seconds to swing a horizontal distance of 18 inches from right to left.

For swing back from left to right, it takes again 2 seconds to cover a horizontal distance of 18 inches.

The total time to complete the one cycle = 4 seconds

Thus, the frequency is the reciprocal of the time

f = 1/4

The expression for the angular speed is:

w = 2πf

w = 2π(1/4)

w = π/2

The distance of the pendulum from the center A = half the horizontal                                  

                                                                                 distance of 18 inches

A = 18/2

A = 9 inches

We know the cosine function for the pendulum is given by:

d = Acosine(wt)

d = 9cosine(πt/2)  or

d = 9cosine[(π/2)t]

Thus, the expression that models d, the horizontal distance in inches of the pendulum from the center as a function of time, t, in seconds is d = 9cosine[(π/2)t]

Learn more about the frequency here:

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Please answer the following??????/

Answers

Answer:

I would be 3 8/10

Step-by-step explanation:

hope this helps

The sum of three numbers is 78. The third number is 7 more than the first. The second number is 3 times the third. What are the numbers?

Answers

Answer:

10+51+17=78

Step-by-step explanation:

Alright, so at first I just took a random number and kept on working it out until I got the exact answer as 78. Finally, i got the third number as 17. Now, i know the third number is 7 more than the first so I have to subtract 17 and 7, 17-7=10. So the first number is 10. Ok, now i know that the second number is 3 times the third number (17) so you should multiply, 17x3=51. 51 is the 2nd number.

1st number=10

2nd number=51

3rd number=17

Add them, 10+51+17=78.

Answer:

First number = 10Second number = 51Third number = 17

Step-by-step explanation:

In the question we are given ,

Sum of three numbers is 78

Third no. is 7 more than first

Second no. is 3 times third

So , we are assuming that ,

Let first no. be x

Third no. be x + 7 ( because in question it is given that third number is 7 more than the first number ) .

Second no. be 3 ( x + 7 ) ( because in the question it is given that second no. is three times the third )

We are finding the solution by adding all these term and equating it with 78 because sum of these three numbers is equal to 78 .

Here we go ,

[tex] \longrightarrow \: x + 3(x + 7) + x + 7 = 78[/tex]

Step 1 : Solving the bracket part :

[tex] \longrightarrow \: \blue{x }+ \blue{ 3x} + \red{21} + \blue{ x} + \red{7 }= 78[/tex]

Step 2 : Adding like terms :

[tex] \longrightarrow \:5x + 28 = 78[/tex]

Step 3 : Transposing 28 to right hand side :

[tex] \longrightarrow \:5x = \green{78} - \green{28}[/tex]

Step 4 : Subtracting 28 from 78 :

[tex] \longrightarrow \:5x = 50[/tex]

Step 5 : Transposing 5 to right hand side :

[tex] \longrightarrow \:x = \cancel \frac{50}{5} [/tex]

Step 6 ; Cancelling 50 with 5 :

[tex] \longrightarrow \: \purple{\boxed{x = 10}}[/tex]

Therefore value of ,

x [ first number ] = 10

3(x + 7 ) [ second number ] = 51

x + 7 [ third number ] = 17

Verification :

We are verifying our answer by adding the three numbers and it must be equal to 78 .

10 + 51 + 17 = 78

61 + 17 = 78

78 = 78

L.H.S = R.H.S

Hence , Verified.

Therefore , our answer is correct .

#Keep Learning

Help me stop bots plsss not bots

Answers

the answer would be 11,137.5 gallons if it needs rounded up it would be 11,138 gallons i believe.

100 pts help pls


Is this triangle acute, right, or obtuse?

acute

right

obtuse

Answers

Thus its an obtuse angle triangle.

=============================

Acute triangle means they measure less than 90°

Right triangle means a triangle with 90°

Obtuse triangle has one angle greater than 90°

Obtuse

Check one angle is streched like it's greater than 90°

Hence one angle is greater than 90 i.e obtuse.

So

it's an obtuse triangle

Julian is a manager at a clothing store for teens. he is analyzing the order for next season. data for the previous 10 years suggests that teens are willing to spend an average of $75 for a pair of designer jeans with a standard deviation of $5. however, julian thinks the average may have changed due to a recession. he finds that the last three seasons of data show that teens spent an average of $68 on a pair of jeans. therefore, he performed a hypothesis test to see if the recent average is the same. julian used a significance level of 5% to perform the test. which of the following statements is valid based on the results? julian’s data shows that the recent seasons’ average jean price is not $75. julian’s data shows that he should order fewer jeans than before. julian’s data shows that the recent seasons’ average jean price is still $75. julian’s data is inconclusive, so he should order the same number of jeans.

Answers

Julian’s data shows that the recent seasons’s average jeans price is not $75.

Julian is a manager at a clothing store for teens.

He is analyzing the order for next season.

What is the average price?

The average price is the mean price of an asset or security observed over some period of time

data for the previous 10 years suggests that teens are willing to spend an average of $75 for a pair of designer jeans with a standard deviation of $5.

however, Julian thinks the average may have changed due to a recession.

The answer is A).

Julian’s data shows that the recent seasons’s average jeans price is not $75.

To learn more about the average price visit:

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Answer:

Julian’s data shows that the recent seasons’ average jeans price is not $75.

Step-by-step explanation:

edge 2022

Last month, korey’s comics had $4,350 in net sales with a gross profit of $3,320 and a net income of $1,850. calculate korey’s net profit margin. a. 42.5% b. 55.7% c. 76.3% d. 179.5% please select the best answer from the choices provided a b c d

Answers

Korey’s gross profit margin last month will be equal to 55.7%.

What is the gross profit margin?

The gross profit margin is a profitability ratio. Profitability ratios measures the efficiency with which a company generates profit from its asset. Gross profit margin measures the return on sales.

Gross profit margin = net income / gross profit

$1850 / 3320 = 0.557 = 55.7%

To learn more about profit margin, please check: brainly.com/question/26208770

Answer:

The answer is actually a. 42.5%

Step-by-step explanation:

Correct on edg. 2022

It costs a zoo $3 to feed the kookaburras for 4 hours. Write an equation relating the total cost y to the number of hours x.

Answers

Answer:

y=0.75x

Step-by-step explanation:

$3 for every 4 hours

$0.75 for every hour

y=0.75x

The equation relating the total cost (y) to the number of hours (x) is y = 0.75x.

The equation that relates the total cost (y) to the number of hours (x) can be derived from the given information. We know that the cost is $3 for 4 hours of feeding kookaburras.

The cost is proportional to the number of hours, and we can represent this relationship using a linear equation:

Cost = Rate × Hours

In this case, the rate is the cost per hour, which is $3 / 4 hours = $0.75 per hour.

Therefore, the equation relating the total cost (y) to the number of hours (x) is:

y = 0.75x

Here, "y" represents the total cost, and "x" represents the number of hours. This equation reflects the linear relationship between the total cost and the number of hours of feeding kookaburras in the zoo.

To know more about equation:

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#SPJ3

Write one statistical question(your data needs to have variability),that you could ask the students in your class that would result in numerical data

Answers

Answer:

ask your classmates what is there shoe sizes are

Step-by-step explanation:

What’s the volume of the figure?

Answers

Answer:

ans below

Step-by-step explanation:

when rectangle is rotated, hemisphere is formed with r =12cm

volume = 2/3πr^3

= 1152π cm^3

Find the volume.

B1=36
B2= 24
Height=38
Length=20

Answers

Answer:

V= 22800 unit^3

Step-by-step explanation:

hope this helps :)

What is the answer for 4/7x5/3x3/4= ?

Answers

Answer:

[tex]\frac{x^{2} }{21}[/tex]

Step-by-step explanation:

1. Combine multiplied terms into a single fraction

2. Eliminate quotient in numerator

3. Multiply the numbers

Solution: [tex]\frac{x^{2} }{21}[/tex]

Answer:

When we multiply 4\7, 5\3 and 3\4, then the answer will be 5\7.

On their birthdays, employees at a large company are permitted to take a 60-minute lunch break instead of the usual 30 minutes. Data were obtained from 10 randomly selected company employees on the amount of time that each actually took for lunch on his or her birthday. The company wishes to investigate whether these data provide convincing evidence that the mean time is greater than 60 minutes. Of the following, which information would NOT be expected to be a part of the process of correctly conducting a hypothesis test to investigate the question, at the 0. 05 level of significance?

Answers

Answer:

Given that the p-value is greater than 0.05, rejecting the null hypothesis and concluding that the mean time was not greater than 60 minutes

Step-by-step explanation:

I got it right on AP Classroom

Pls help algebra 1

A clerk earns $125 per day, plus a commission equal to
10% of her sales, s. The clerk earns less than $180 on
Monday
Enter an inequality that represents all possible values for
the clerk's sales, s, on Monday.

Answers

Answer:

0.1s + 125 < 180

7/10 of the books sold by the used book store had hardback covers. 2/3 of those had been repaired. What part of the books sold had repaired hardback covers?

Answers

Answer:

7/15

Step-by-step explanation:

2/3 of those means 2/3 of the 7/10 books sold by the used book store

2/3 of 7/10 means 2/3 * 7/10 = 14/30 = 7/15

Hope this helps :)

Have a nice day!

Will name brainliest!

Answers

Answer:

B as the number of molecules increases the volume increases

Step-by-step explanation:

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Patti puts 40 marbles in a bag. Each marble has a mass of 3 grams. What is the total mass of the bag of marbles? Show work 100 POINTS WILL MARK BRAINLIEST NEED BY 9:00 To ____ a project, you must finalize all activities and transfer the completed or canceled work to the appropriate people. My only ________________ is talking on the phone too long. i really need help i have had the worst day and i just need help on one question please What is the surface area of a cylinder that is 5 centimeters highand has a diameter of 1.5 centimeters?7.57 cmB 8.6257 cmC 10.57 cmD 19.557 cm A body moving in the positive x direction passes the origin at time t = 0. between t = 0 and t = 1 second, the body has a constant speed of 24 meters per second. at t = 1 second, the body is given a constant acceleration of 6 meters per second squared in the negative x direction. the position x of the body at t = 11 seconds is How did the columbian exchange affect Europeans? How does the work done on a machine compare to the work done by a machine? #3. Using the table of values, which equation represents the linearfunction? *: -2, 0, 2, 4, 6: 1, -9, -19, -29, -39O y = -x + 10O y = 10x + 1O y=-10x - 9O y=-5x - 9 All of the following students are attempting to limit their speech topics except: a. justin writes the word ""psychology"" at the top of a piece of paper. he then draws two lines down and writes ""marriage Carl rogers' view of self-concept includes all of the following except __________. a. self-understanding b. personal likes and dislikes c. personal strengths and weaknesses d. biological urges please select the best answer from the choices provided a b c d the mathematical answer of 1+1 Find the area of the circle. Round your answer to two decimal places, if necessary. (religion) 30 pts need help with this help is very much appreciated Summarize why Malcolm X wants Black people to use self-defense. Chris has 7/8 yard of purple ribbon and 1 1/6 yards of green ribbon. Chris has a total of 3 2/3 yards of ribbon. How many yards of Chris's ribbon are neither purple nor green?A. 23/24B. 1 5/8C. 2 1/24D. 2 1/2 Question 1 (5 points)Where does math processing largely take place in the brain?Right parietal lobeLeft parietal lobeO Frontal LobeO Occipital Lobe HELPP FAST!!! URGENT!!Of the 1250 students registered at the local high school, 30% of them did not vote during the student body elections. How many students did not vote?A) 350B) 425C) 365D) 375 These reforms were instituted by - question 4 options: governors during the colonial era reconstruction governments after the civil war patriots during the american revolution revivalists after the second great awakening