Question

NEED HELP ASAP! 40 POINTS!

Answer 1

Same height when both equations are equal

-16x^2 +  74x + 9 = -16x^2 + 82x

82x - 74x = 9

8x = 9

x = 9/8

x = 1.125

x = 1.13 ---->rounded to nearest hundredths of seconds

answer

1.13 seconds

Answer 2

Since the functions represent the heights of the rockets, and we are trying to find when the heights are the same, we essentially just want to know where the functions equal each other.

To find this, let's set both functions equal to each other and solve:

$-16x^2 + 74x + 9 = -16x^2 + 82x$

• Set up equation

$74x + 9 = 82x$

• Add $16x^2$ to both sides of the equation

$9 = 8x$

• Subtract $74x$ from both sides of the equation

$\boxed{x = \dfrac{9}{8}}$

• Divide both sides of the equation by 8

Our answer is 9/8 seconds, or approximately 1.13 seconds.