Logarithms and stuff, please help

Logarithms And Stuff, Please Help

Answers

Answer 1

Answer:

[tex]\displaystyle t=-25\log\left(\frac{20}{30}\right)[/tex]

Step-by-step explanation:

Logarithms

The model that predicts the percentage of voters (V) as a function of the number of years (t) is:

[tex]V(t)=100-30\cdot e^{-0.04t}[/tex]

It's required to find in how many years the value of V will be V=80%. The equation to solve is:

[tex]100-30\cdot e^{-0.04t}=80[/tex]

Subtracting 100:

[tex]-30\cdot e^{-0.04t}=80-100=-20[/tex]

Dividing by -30:

[tex]\displaystyle e^{-0.04t}=\frac{20}{30}[/tex]

Applying logs:

[tex]\displaystyle \log( e^{-0.04t})=\log\left(\frac{20}{30}\right)[/tex]

For logs property:

[tex]\displaystyle -0.04t\log(e)=\log\left(\frac{20}{30}\right)[/tex]

log(e)=1. Solving for t:

[tex]\displaystyle t=\frac{\log\left(\frac{20}{30}\right)}{-0.04}[/tex]

Since 0.04=1/25:

[tex]\boxed{\displaystyle t=-25\log\left(\frac{20}{30}\right)}[/tex]


Related Questions

thats all of my points plz help me

Reuben is making a replica of the US flag for his school project.
He uses a scale of 0.5 centimeter to 1 inch to draw the flag. The length of the scale drawing is 2.5 centimeters, and its width is 4.75 centimeters.
The perimeter of the scale drawing is (a7.25, b 11.875, c 14.5 d 47.5)centimeters
The perimeter of the actual flag is(a 14.5 b 29 c 47.5 d 95

Answers

Given: U.S Flag - rectangle in shape

scale of 0.5 cm = 1 in

length of the scale 2.5 cm

width of the scale 4.75 cm

perimeter of the scale = 2(L+W) = 2(2.5+4.75) =

2(7.25) = 14.5cm

perimeter of the actual flag is:

14.5cm * 1in/0.5cm = 29 inches

hope it helps!

Step-by-step explanation:

Perimeter of scale drawing

= 2 * (Length + Width)

= 2 * (2.5cm + 4.75cm)

= 2 * 7.25cm

= 14.5cm. (C)

Scale length to Actual length = 0.5cm : 1 in

Hence,

Perimeter of actual drawing

=> (1/0.5) * Perimeter of scale drawing

=> (1/0.5) * 14.5cm

=> 29 in. (B)


Brainliest if right

Answers

Answer:

the answer is B

Step-by-step explanation:

This year, Carlos planted 6 more than one-third of the cucumber plants he planted last year. How many cucumber plants
did he plant this year if last year he planted 12 plants?
06
9
O 10
O 12

Answers

Answer:

10.

Step-by-step explanation:

6+1/3*12=6+4=10

Answer: 10

Step-by-step explanation:

If matrix C represents (A-B)+A, the value of the entry represented by C41 is

Answers

Answer:

The value of the entry represented by [tex]c_{41}[/tex] is 12.

Step-by-step explanation:

Let [tex]A = \left[\begin{array}{ccc}-5&3&8\\3&6&-5\\5&-9&0\\7&3&4\end{array}\right][/tex] and [tex]B = \left[\begin{array}{ccc}-7&-8&-5\\7&9&2\\2&5&-7\\2&8&-7\end{array}\right][/tex]. The sum of equal-sized matrices consist in the sum of each pair of corresponding elements. If [tex]C = (A-B)+A[/tex], then:

[tex]C = 2\cdot A -B[/tex] (1)

Then, [tex]c_{41}[/tex] is the element of matrix C located in the fourth row and first column and is defined by the following expression:

[tex]c_{41} = 2\cdot a_{41}-b_{41}[/tex] (2)

If we know that [tex]a_{41} = 7[/tex] and [tex]b_{41} = 2[/tex], then [tex]c_{41}[/tex] is:

[tex]c_{41} = 2\cdot (7)-2[/tex]

[tex]c_{41} = 12[/tex]

The value of the entry represented by [tex]c_{41}[/tex] is 12.

A line passes through (-2,5) and has slope. What is an equation of the line in point-slope form?

Answers

Answer:

Step-by-step explanation:

since the question does not have a given slope you can just put the point into the point slope formula   y-y1 = m(x-x1)  

y-5 = m(x-(-2))

y-5 = m(x+2)

since the slope is not given, leave it like that

Can you help me out with this question pls

Answers

B I’m not sure if I’m right

Winston wants to put some very thick books on his bookshelf. Each book is 3 inches
thick. His bookshelf is 16 inches wide. How many thick books can he put on the
bookshelf? (There will be space left over.)
5
1
15
6

Answers

I believe u can put 5 books on there

Please help ASAP PLEASE AND THANK YOUUU ❤️

Answers

Step-by-step explanation:

[tex] {7}^{ - 3} \times {7}^{ - 5} \times 7 {}^{ - 1} [/tex]

[tex] \frac{1}{7 {}^{3} } \times \frac{1}{ {7}^{5} } \times \frac{1}{7 } \\ \frac{1}{ {7}^{3 + 5 + 1 } } \\ \frac{1}{ {7}^{9} } \\ [/tex]

[tex] = \frac{1}{ {7}^{9} } [/tex]

Step-by-step explanation:

[tex] = {7}^{ - 3} \times {7}^{ - 5} \times {7}^{ - 1} [/tex]

[tex] = {7}^{( - 3 - 5 - 1)} [/tex]

[tex] = {7}^{ - 9} [/tex]

[tex] = \frac{1}{ {7}^{9} } [/tex]


Help !! No work is needed to be shown

Answers

Step-by-step explanation:

By Law of Indices, a^m / a^n = a^(m-n).

Therefore a² / a⁸ = a^(-6).

x = -6.

Identify the two equations that have no solution?

Answers

Answer:

1st option and last option

Salma's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs Salma $5.15 per pound, and type B coffee costs $4.10 per pound. This month, Salma made 147 pounds of the blend, for a total cost of $659.40. How many pounds of type A coffee did she use?

Answers

.........................

Answer: 54 pounds

Step-by-step explanation:

1. Adressing the variables:

x=number of pounds of type A

y=number of pounds of type B

2. Equations:

x+y=147 pounds

5.15x+4.1y=659.40

3. Subsitution:

y=147-x =>5.15x+4.1(147-x)

4. Solve:

5.15x+602.7-4.1x=659.4

=> 1.05x=56.7 => x=54

5. Solution:

x=54; y=93

There are 60 marbles in a bowl. Their colors are red, blue, and yellow. 1/3 of the marbles are yellow, 1/4 of the marbles are blue. How many red marbles are there in the bowl

Answers

Answer: 25 red marbles

Step-by-step explanation:

Fraction of yellow marbles = 1/3

Fraction of blue marbles = 1/4

Fraction of red marbles = 1 - (1/3 + 1/4) = 5/12

Therefore, the number of red marbles that are there in the bowl would be:

= 5/12 × 60

= 25 red marbles

For 6 consecutive days, Alejandro studied for 5 minutes more each day than he did the previous day. Which best represents the change in the amount of time that Alejandro studied on the first day to the amount of time he studied on the last day?
–30 minutes
–11 minutes
11 minutes
30 minutes

Answers

Answer:

30 minutes

Step-by-step explanation:

Option A.30 minutes.

The change in the amount of time that Alejandro studied on the first day to the amount of time he studied on the last day is 30 minutes.

Step-by-step

The computation of the change in the amount of time is shown below = Number of consecutive ways * number of minutes more each day = 6 days ~ 5 minutes = 30 minutes

Hence, the change in the amount of time is 30 minutes Therefore the correct option is D.

We simply applied the above formula so that the correct value could come, and the same is to be considered(the answer is 30 ).

Learn more about consecutive days at

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#SPJ2

100 points with work

Answers

Answer:

jacky 12 809 n-t

Step-by-step explanation:

Answer:

he said it not me

1) △ABC has A(-2,-2), B(-1,2) and C(2,1). After a dilation centered at the origin, △A'B'C' has A'(-4,-4), B'(-2,4) and C'(4,2). What is the scale
factor of the dilation?
a) -2
C) 2
b) -1/2
d) 1/2

Answers

Answer:

Option (C)

Step-by-step explanation:

If a point is dilated by a scale factor of 'k' about the origin,

Rule for the dilation,

(x, y) → (kx, ky)

By this rule, if ΔABC is dilated to form image triangle as ΔA'B'C',

A(-2, -2) → A'[2×(-2), 2×(-2)]

B(-1, 2) → B'[2×(-1), 2×(2)]

C(2, 1) → C'[2×(2), 2×(1)]

Therefore, scale factor of the dilation of the dilation will be k = 2

Option (C) will be the answer.

-16>-f , if f =15 true or false

Answers

Answer:

false 15 is a positive number

Combine Like Terms
5+2x+5+7x=3​

Answers

Answer:

9x + 10 = 3

General Formulas and Concepts:

Algebra I

Combining Like Terms

Step-by-step explanation:

Step 1: Define Equation

5 + 2x + 5 + 7x = 3

Step 2: Simplify

Combine like terms (x):                    9x + 5 + 5 = 3Combine like terms (Z):                    9x + 10 = 3

Answer:

9x+10=3

Explantion

(2x+7x)+(5+5)=3

= 9x+10=3

Given DFG, mD=48° mF=75°, FG= 20 Find DF,DG

Answers

Answer:

DF=22.57

DG=26

Step-by-step explanation:

sinF/DG=sinD/FG

sin75/DG=sin48/20

DG*sin48/sin48=20*sin75/sin48

DG=26

D^+F^+G=180(sum of int. angles of triangle)

G^=180-48-75

G^=57

sinG/DF=sinD/FG

sin57/DF=sin48/20

DF*sin48/sin48=20*sin57/sin48

DF=22.57

The value of DF and DG is 22.57 units and 25.9956 units respectively.

Given to us,

∠D = 48°,

∠F = 75°,

FG = 20,

According to sine rule, in a triangle the length of a side of the triangle and the angle opposite to it is always in ratio. therefore,

[tex]\dfrac{A}{sin\alpha}= \dfrac{B}{sin \beta}= \dfrac{C}{sin\gamma}[/tex]

So,

[tex]\dfrac{DF}{sin (G)}= \dfrac{FG}{sin (D)}= \dfrac{GD}{sin(F)}[/tex],

For ∠G,

∠D + ∠F + ∠G = 180°,

48° + 75° + ∠G = 180°,

∠G = 180° - ( 48° +75°),

∠G = 57°,

Now using the sine rule,

[tex]\dfrac{DF}{sin (G)}= \dfrac{FG}{sin (D)}= \dfrac{DG}{sin(F)}\\\\\\\dfrac{DF}{sin (57)}= \dfrac{20}{sin (48)}= \dfrac{DG}{sin(75)}\\\\\\\dfrac{DF}{sin (57)}= \dfrac{20}{sin (48)}\\\\DF = 22.57\ units\\\\\\ \dfrac{20}{sin (48)}= \dfrac{DG}{sin(75)}\\\\DG = 25.9956\ units[/tex]

Hence, the value of DF and DG is 22.57 units and 25.9956 units respectively.

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Jenna has 3 red balloons and 5 blue balloons.
what is the ratio of the blue balloons. she adds 2 red balloons and remove 1 blue balloons what is the new ratio of the number of red balloons to the number of blue balloon ​

Answers

Answer:

5: 4

Step-by-step explanation:

original ratio: 3:5

new ratio: 5:4

hope it helps!

An object of mass 20kg is dropped from a height . Find the potential and kinetic energy if the heights are 4,3,2,1, just above the ground. (Take value of g as 10 m/s-2

Answers

Answer:

At 4 meters, the potential energy is 800 Joules

At 3 meters, the potential energy is 600 Joules

At 2 meters, the potential energy is 400 Joules

At 1 meter, the potential energy is 200 Joules

Step-by-step explanation:

The given mass of the object = 20 kg

The Potential Energy of an object at a height is. P.E. = m × g × h

Where;

m = The mass of the object

g = The acceleration due to gravity taken as 10 m/s²

h = The height of the object

The potential energy if the height is 4 meters is given as follows;

P.E. = 20 kg × 10 m/s² × 4 m = 800 Joules

The potential energy if the height is 3 meters is given as follows;

P.E. = 20 kg × 10 m/s² × 3 m = 600 Joules

The potential energy if the height is 2 meters is given as follows;

P.E. = 20 kg × 10 m/s² × 2 m = 400 Joules

The potential energy if the height is 1 meter is given as follows;

P.E. = 20 kg × 10 m/s² × 1 m = 200 Joules.

Tyrese bought 35 tickets to use at the carnival. He used some of the tickets to ride the bumper cars and play some games. now he has 28 tickets left what is the percent of decrease in the number of ticket that he has?

Answers

Answer:

20%?

Step-by-step explanation:

How long will it take l to catch up to c lauren can run 24 feet in 3 seconds clara can run 20 feet in 5 seconds clara has a 40 foot head start l will catch c in how many seconds after running how many feet

Answers

Answer:

They both will meet each other when they both have been running for 10 seconds

Lauren will run [tex]x=80\ \text{ft}[/tex] and Clara will run [tex]40\ \text{ft}[/tex]

Step-by-step explanation:

Velocity of Lauren

[tex]v_l=\dfrac{24}{3}\\\Rightarrow v_l=8\ \text{ft/s}[/tex]

Velocity of Clara

[tex]v_c=\dfrac{20}{5}\\\Rightarrow v_c=4\ \text{ft/s}[/tex]

Let distance traveled by Lauren be [tex]x[/tex]

As Clara has a 40 feet head start distance she will travel is [tex]x-40[/tex]

[tex]\text{Time}=\dfrac{\text{Distance}}{\text{Speed}}[/tex]

The time that will have passed when they both will meet will be the same for both of them so

[tex]\dfrac{x-40}{4}=\dfrac{x}{8}\\\Rightarrow 8x-320=4x\\\Rightarrow 8x-4x=320\\\Rightarrow 4x=320\\\Rightarrow x=\dfrac{320}{4}\\\Rightarrow x=80\ \text{ft}[/tex]

Time they will meet is [tex]\dfrac{80-40}{4}=\dfrac{80}{8}=10\ \text{s}[/tex].

So, Lauren will run [tex]x=80\ \text{ft}[/tex] and Clara will run [tex]x-40=80-40=40\ \text{ft}[/tex].

help math 7th grade.........​

Answers

Answer:

6/7

Step-by-step explanation:

Answer: 6/7

Step-by-step explanation:

Joe baked 27 dozen cookies and 24 dozen brownies. There are 12 treats in 1 dozen. About how many treats did he bake? Explain.​

Answers

Answer:

612

Step-by-step explanation:

you multiply 27 x 12 and 24 x 12, and add up the products, and you get 612

Answer: 612 Treats

Work: To find out how many treats he baked, you do 27 x 12 and 24 x 12. After doing so, you get 324 and 288. Add those up, and you get 612.

I hope this helps, and Happy Holidays! :)

otieno is k years old.He is 5 years older than kidole what will be their age fours to come​

Answers

Answer:

Otieno's age in 4 years: [tex]k+4[/tex]

Kidole's age in 4 years: [tex]k-1[/tex]

Step-by-step explanation:

[tex]k[/tex] = Otieno's age

[tex]k-5[/tex] = Kidole's age

Their ages will increase by 4 years when 4 years pass.

[tex]k+4[/tex] = Otieno's age in 4 years

[tex]k-5+4[/tex] = Kidole's age in 4 years

[tex]k-1[/tex] = Kidole's age in 4 years (after simplifying the expression)

I hope this helps!

I need help with Thai question

Answers

Answer:

[tex] \Large{\boxed{\sf n = 8}} [/tex]

[tex] \\ [/tex]

Explanation:

The perimeter of a rectangle is given by the following formula:

[tex] \Large{\sf P = 2L + 2W } [/tex]

Where:

P is the perimeter of the rectangle.L is its length.W is its width.

[tex] \\ [/tex]

[tex] \Large{\boxed{\sf Given \text{:} } \begin{cases} \sf L &=\sf 3n - 9 \\ \sf W &=\sf n + 5 \\ \end{cases} } [/tex]

[tex] \\ [/tex]

Substitute these values into our formula:

[tex] \sf P = 2(3n - 9) + 2(n + 5) [/tex]

[tex] \\ [/tex]

Expand the expression of the perimeter using the following distributive property.

[tex]\green{\begin{gathered}\begin{gathered} \\ \boxed { \begin{array}{c c} \\ \blue{ \sf\boxed{ \sf Distributive \: property \text{ : } }} \\ \\ \sf\star \: \red{ \large{ a (b + c) = ab + ac }} \end{array}}\\\end{gathered} \end{gathered}}[/tex]

[tex] \\ [/tex]

We get:

[tex] \sf P = 2(3n) + 2(-9) + 2n + 2(5) \\ \\ \sf P = 6n - 18 + 2n + 10 \\ \\ \boxed{\sf P = 8n - 8 } [/tex]

[tex] \\ [/tex]

Since the perimeter is equal to 56, the value of n satisfies the following equality:

[tex] \sf 8n - 8 = 56 [/tex]

[tex] \\ [/tex]

To solve this equation, let's add 8 to both sides:

[tex] \sf 8n - 8 + 8 = 56 + 8 \\ \\ \sf 8n = 64 [/tex]

[tex] \\ [/tex]

Now, divide both sides of the equation by 8:

[tex] \sf \dfrac{8n}{8} = \dfrac{64}{8} \\ \\ \\ \boxed{\boxed{\sf n = 8}} [/tex]

[tex] \\ \\ [/tex]

▪️Learn more about equations here:

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Two trains leave stations 320 miles apart at the same time and travel toward each other. One train travels at 105 miles per hour while the other travels at 95 miles per hour. How long will it take for the two trains to meet?

Answers

Answer:

1.6 hours / 1 hour 36 minutes

Step-by-step explanation:

105+95=200 miles

This is the distance that the trains could travel in an hour.

320÷200=1.6 hours

Our Answer is 1.6 hours / 1 hour 36 minutes

A store buys a video game for the wholesale price of $29.95. The markup on the game is 80%. If sales tax is 7.5%, how much money would you need to buy the game?

Answers

Answer:

57.9532

Step-by-step explanation:

Given that:

Wholesale price = 29.95

Markup = 80%

Sales tax = 7.5%

Retail price of the game :

Price before sale tax:

Wholesale price * ( 1 + markup %)

29.95 * (1 + 0.8)

29.95 * (1.8)

$53.91

Sales tax = 7.5%

53.91 * (1 + 0.075)

53.91 * (1.075)

= 57.9532

Hence, $57.9532 will have to be paid

I am confused on these 2​

Answers

Answer:

1) x=20 degrees

2) x=25 degrees

Step-by-step explanation:

1) there is 9x if you add all of the angles together and there is 180 degrees in a triangle so 180 divided by 9 equals 20 degrees.

2)there is 7x and 5 dgress in total so we can make an equation:

7x+5=180

7x=175

x=25

What are the domain and range of the function represented by the set of ordered pairs? \ (-6,5),(-3,2),(-1,0),(5,-4)\

Answers

Answer:

The domain and the range of the function represented by the set of ordered pairs are {-6, -3, -1, 5} and {5, 2, 0, -4}

Step-by-step explanation:

In any set of ordered pairs,

The domain is the values of x (set of x) ⇒ the first number in each ordered pairThe range is the value of y (set of y) ⇒ the second number in each ordered pair

Let us solve the question

∵ The set of ordered pairs is {(-6, 5), (-3, 2), (-1, 0), (5, -4)}

∵ The first number in each ordered pair represents x

x = -6, -3, -1, 5

∵ The set of x is the domain of the function

The domain of the set of ordered pairs = {-6, -3, -1, 5}

∵ The second number in each ordered pair represents y

y = 5, 2, 0, -4

∵ The set of y is the range of the function

The range of the set of ordered pairs = {5, 2, 0, -4}

The domain and the range of the function represented by the set of ordered pairs are {-6, -3, -1, 5} and {5, 2, 0, -4}

Answer:

Domain: {-6,-3,-1,5}

Range: {-4,0,2,5}

Step-by-step explanation:

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