The height, in feet, of a t-shirt launched from a t-shirt cannon high in the stands at a football stadium is given by h (x) = -16x^2+64x+80, where x is the time in seconds after the t-shirt is launched. How long will it take for the t-shirt to reach the ground?

Question

Deshawn Shelton

Mathematics

22 June, 15:49

The height, in feet, of a t-shirt launched from a t-shirt cannon high in the stands at a football stadium is given by h (x) = -16x^2+64x+80, where x is the time in seconds after the t-shirt is launched. How long will it take for the t-shirt to reach the ground?

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Answers (1)

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Donte Dyer · Answer 1

5 seconds.

Step-by-step explanation:

The first thing we can do is convert h (x) into 0. - 16x²+64x+80=0

Then, factor out - 16, as both 64 and 80 are divisible by 16.

This leaves you with x²-4x-5=0.

Then, you factor that expression to get (x+1) (x-5).

Convert those to x+1=0 and x-5=0.

Your answers will be x = - 1 and x = 5, but since we cannot have a negative time, 5 is the only correct option.