Answer:
They are at the same height at 1.13 seconds.
Step-by-step explanation:
Remark
The rockets are at the same height when f(x) = g(x) [see below] are the same. So you can equate them.
Givens
f(x) = - 16x^2 + 74x + 9
g(x) = -16x^2 + 82x I have changed this so you don't have 2 f(x)s
Solution
- f(x) = g(x)
- -16x^2 + 74x + 9 = -16x^2 + 82x Add: 16x^2 to both sides
- -16x^2+16x^2+74x + 9 = -16x^2+16x^2 + 82x Combine terms
- 74x + 9 = 82x Subtract 74x from both sides
- 74x - 74x + 9 = 82x - 74x Combine
- 9 = 8x Divide by 8
- 9/8 = 8x/8
- x = 1 1/8 Convert to decimal
- x = 1.125
- x = 1.13 [rounded]
