Can y’all plz help me

Mathematics

2 answers:

Ksenya-84 [330]3 years ago

7 0

2r-9=-18
+9 +9
2r= -9
The answer is r=-9

Sever21 [200]3 years ago

7 0

Answer: 4.5

Step-by-step explains: 1) 2r - 9 = -18

2r - 9 + 9 = -18 + 9

2) ( 9 + 9 ) Add the numbers

( -18 + 9 ) add the numbers

2r = -9

3) Divide both sides of the equation by the same term

4) Cancel terms that are in both the numerator and denominator

r = 9/2 = 4.5

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A raffle prize of 14x^2/15dollars is to be divided among 7x people. Write an expression for the amount of money that each person

vladimir2022 [97]

For this case we must divide the following expression:

$\frac {\frac {14x ^ 2} {15}} {7x}$

And in this way we get the amount of money that each person will receive.

Then applying double C we have:

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Thus, each person has 0.133x of money!

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7 0

4 years ago

What are the amplitude, period, and midline of f(x)=-4 cos (2x-n)+3?

tangare [24]

To find the amplitude and period you need to be familiar with the following equation. Also you need to know that the standard cos has a period of $2\pi$ and the midline is a line that runs between the max and min of the y-values of the function.

Equations:
f(x) = A cos(Bx +C) + D
f(x) = -4 cos(2x -n) + 3

A = amplitude = |-4| = 4
B = 2
C = phase shift = n = 0
D = vertical shift = midline = 3

Amplitude = 4

Find the period:
$Period = \frac{2\pi}{B} = \frac{2\pi}{2} = \pi$

Find the midline:
We know that the amplitude is 4 so we have a range from -4 to 4. The standard y = cos(x) has its midline at 0 so y = 0. This is also true for y = -4 cos(x). In your equation though, you have a vertical shift of +3 so this changes our midline. With an amplitude of 4, which gives us a range from -4 to 4(our y-values), the shift moves this up by 3 so that means we will have new y-values and a range of -1 to 7. Now we need to find the midline(the middle of our y-values) of our new range. We can find this by using the following formula
$Midline = \frac{Y_1 + Y_2}{2} = \frac{-1+ 7}{2} = \frac{6}{2} = 3$

Midline:
y = 3

Note, in the following equations that D = 3 = midline

y = A (Bx+C) + D
y = -4 (2x + n) + 3

Also, the picture that is attached is what your equation looks like when graphed.