Iron is an important element it is found in the food we eat and it’s used to make things like buildings and bridges

The quadratic equation –x2+3x+c =0 does not have any real solution for c<-9/4.

The given quadratic equation is:

[tex]-x^{2} +3x+c=0[/tex]

Any equation is called a quadratic equation if it has a form [tex]ax^{2} +bx+c=0[/tex] and a≠0.

For no real solution, the discriminant of a quadratic equation should be less than zero.

[tex]D < 0[/tex]

[tex]3^{2} -4(-1)(c) < 0[/tex]

[tex]9+4c < 0[/tex]

[tex]c < \frac{-9}{4}[/tex]

The quadratic equation –x2+3x+c =0 does not have any real solution for c<-9/4.

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Answer:

–5 and -9/2 or the first and second options

Answer: 12

Step-by-step explanation:

Answer:

68

Step-by-step explanation:

Khan

C and D are the two square matrices

C + D

then the answer is A

☆...Hope this helps...☆

Answer:

189

Step-by-step explanation:

9 x 9 is 81 for the square. for the triangles it is 9 x 6 divided by 2 which is 24. for all 4 we do 24 x 4 which gets 108. 108 + 81 = 189

Answer:

Below in bold.

Step-by-step explanation:

We find fg(x) by replacing the x in f(x) by g(x), so:

fg(x) = (4x - 2a)^2 + 4a(4x - 2a) + a^2

fg(3) = 89 so:

(4(3) - 2a)^2 + 4a(4(3) - 2a) + a^2 = 69

(12 - 2a)^2 + 48a - 8a^2 + a^2 - 69 = 0

144 - 48a + 4a^2 + 48a - 8a^2 + a^2 - 69 = 0

-3a^2  + 75 = 0

-3a^2  = -75

a^2 = 25

a = 5.

Now g(x) = 4x - 2(5) = 4x - 10.

Finding g-1(x);

4x = g(x) + 10

x = (g(x) + 10)/4

So g-1(x) = (x + 10)/4

When g-1(x)= x

x = (x +10)/4

4x = x + 10

3x = 10

x = 10/3.

The product of the expression (-3s + 2t) and (4s - t) is -12s² + 11st -2t². Then the correct option is D.

It is also known as multiplication. If the object n is given to m times then we just simply multiply them.

The expression is given below.

(-3s + 2t) and (4s - t)

Then the product of the expression (-3s + 2t) and (4s - t) is given as

(-3s + 2t)(4s - t)

-12s² +3st + 8st - 2t²

-12s² + 11st -2t²

More about the product link is given below.

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Answer:

c

Step-by-step explanation:

becasue it would have a 3/8 chance of landing on silver , 8 goes into 240 30 times. so if we multiply 3 by 30 it gives us 90.

Answer:1/8

Step-by-step explanation:

well the total amount you have of cards is 36 so you will have 4/36 now you just need to reduce and you will get 1/8

Answer:

23

Step-by-step explanation:

Set Thomas' age to be variable x.

Since Huilan is 3 times the age of Thomas, he is 3x.

3x + x = 92 (The sum of their age)

4x = 92

4x/4 = 92/4   (Isolate x)

x = 23

Extra information: Huilan is 69 because 23 x 3 = 69

Answer:

8ft

Step-by-step explanation:

Answer:

3

Step-by-step explanation:

We will see that the surface area of the triangular pyramid is equal to 170.1 yd^2

Remember that the area of a triangle is equal to:

A = (1/2)*b*h

Where b is the base, and h is the height.

On the triangular pyramid, we have 3 faces with a base of 9 yards and a height of 10 yd, so the area of these 3 faces is:

A  = (1/2)*(10 yd)*(9 yd) = 45 yd^2

Also, we can see that the bottom face has a base of 9 yards and a height of 7.8 yards, then its area is:

A' = (1/2)*(9 yd)*(7.8 yd) = 35.1 yd^2

So the total surface area of the pyramid is:

S = 3*A + A' = 3*45 yd^2 + 35.1 yd^2 = 170.1 yd^2

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12 ft

Using 13 for c, and 5 for a, you can use Pythagorean’s theorem a^2+b^2=c^2 to find b, the height

5^2+b^2=13^2

25+b^2=169

b^2=144

b = 12

Answer:

230

Step-by-step explanation:

SA=2(lw+hw+lh), where

l=length

h=height

w=width

2(5*5+9*5+5*9) = 230

Answer:

x≤5

Step-by-step explanation:

When multiplying an inequality by a negative number, make sure to reverse the inequality signs. If -x has to be greater or equal to -5, then x has to be lesser or equal to 5

Answer:

25r+50s-25

Step-by-step explanation:

5(5r+10s−5)

we can follow distributive law

5*5r+5*10s+5(-5)

25r+50s-25

Answer:

301+

Step-by-step explanation:

The answer can be anything above 300. This means the answer could be 301, or 400, or 350000000000, any of those are correct.

Answer:

Step-by-step explanation:

Answer:

y = -4x + 7

Step-by-step explanation:

slope-intercept form of a linear equation:  y = mx + b

(where m is the slope and b is the y-intercept)

Given:

⇒ y = -4x + 7

The two ways which can be used to increase the power of this test is to: A. increase the sample size and increase the significance level.

In Statistics, power can be defined as the probability that a deviation from the null hypothesis would be detected by a test of significance, if such a deviation exist.

This ultimately implies that, the statistical power of a hypothesis test refers to the probability of correctly rejecting the null hypothesis provided it is false.

In this cenario, the two ways which can be used to increase the power of this test is by increasing the sample size and increasing the significance level.

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Answer: A

Step-by-step explanation:

edge

Step-by-step explanation:

2 pi r = 34.6

2 r = 34.6/3.14

d = 11 m

Diameter be d

Answer:

I subtracted the highest and lowest numbers. The range for new cars was 31. The range for old cars was 75. The range for used cars was much bigger.

Hope's this helps you.

Step-by-step explanation:

Answer:

It’s also worth pointing out that the presentation of the algebraic expressions in coin word problems are a bit different and not so straightforward compared to what we’re used to. For example, instead of saying “the number of nickels is 2 more than the number of dimes“, you’ll often see this expressed in coin word problems as “there are 2 more nickels than dimes“. Both algebraic expressions can be written in an equation as n=d+2n=d+2 but just expressed differently.

Step-by-step explanation:

Tamara has 35 coins in nickels and quarters. In all, she has $4.15. How many of each kind of coin does she have? Right off the bat, the problem gives us two important pieces of information. First, it tells us that there is a total number of 35 coins consisting of nickels and quarters. Secondly, the total value of the coins is $4.15. We need to translate these statements into algebraic equations to find how many nickels and how many quarters she has.

BTW hope this helps

Check the picture below.

so the solid produced will be a cylinder with a hole in the middle, like you see in the picture, hmmm so we could get its volume by simply getting the outer cylinder and subtracting the inner cylinder, or we can just get the volume of the ring on the left and multiply it by its length, so let's do the that.

[tex]\textit{volume of a ring}\\\\ V=\pi (R^2-r^2)~~ \begin{cases} R=\stackrel{larger}{radius}\\ r=\stackrel{smaller}{radius}\\[-0.5em] \hrulefill\\ R=3\\ r=1 \end{cases}\implies V=\pi (3^2-1^2)\implies V=8\pi \\\\\\ \stackrel{\textit{\large volume of the hollow cylinder}}{\stackrel{\textit{volume of the ring}}{(8\pi )}\qquad \stackrel{length}{(6)}\implies 48\pi ~~\approx~~150.80}[/tex]

Answer: A' (1, 5)

B' (-3, 5)

C' (-3, 2)

D' (1, 2)

Step-by-step explanation:

To reflect across the y-axis the original point (x, y) must become (-x, y) which is essentially taking the opposite of x

We can do that with each of the point of the rectangle ABCD to make the reflect rectangle A'B'C'D'

A (-1, 5) to A' (1, 5)

B (3, 5) to B' (-3, 5)

C (3, 2) to C' (-3, 2)

D (-1, 2) to D' (1, 2)

Answer:

[tex]\huge\boxed{\sf 6xy-3x^2}[/tex]

Step-by-step explanation:

Given Expression:

(x + y)² - (x - y)² + 2xy - 3x²​

Formulas used:

Expand the above expression according to the formulas

[tex]=x^2+2xy+y^2-(x^2-2xy+y^2)+2xy-3x^2\\\\= x^2+2xy+y^2-x^2+2xy-y^2+2xy-3x^2\\\\cancel \ out \ x^2 \ and \ y^2\\\\= 2xy+2xy+2xy-3x^2\\\\= 6xy-3x^2\\\\\rule[225]{225}{2}[/tex]

Answer:

see explanation

Step-by-step explanation:

to clear a square root on the denominator

Multiply the numerator and denominator by the square root, for example

[tex]\frac{5}{\sqrt{3} }[/tex]

= [tex]\frac{5}{\sqrt{3} }[/tex] × [tex]\frac{\sqrt{3} }{\sqrt{3} }[/tex] = [tex]\frac{5\sqrt{3} }{3}[/tex]

Answer:

See answers below

Step-by-step explanation:

Entire outer circle area = pi r^2   = pi 18^2 =  324 pi cm^2

   if you subtract the small unshaded circle you get 299 pi

    324 pi  - smaller circle = 299 pi

      smaller circle = 25 pi  cm^2

Answer:

42

Step-by-step explanation:

6 x 6 is 36. 3 x 2 is 6. 36 + 6 is 42.

Answer:

8.29 miles

Step-by-step explanation:

1 mile= 4*1/4=0.30*4=1.20

11=2.25+1.20(m-1)

8.75=1.20(m-1)

7.29=m-1

8.29=m