Question

HELP ME DO THIS PLZ

Answer 1

It landed at a height of 14 feet

Explanation:

Given

`y = -(1)/(8)x^2 +4x` --- Path of a t-shirt

`3y = 2x - 14` --- height of bleachers

Required

Height when t-shirts land in bleachers

`3y = 2x - 14`

Make y the subject

`y = (2)/(3)x - (14)/(3)`

Substitute
`y = (2)/(3)x - (14)/(3)` in
`y = -(1)/(8)x^2 +4x`

`(2)/(3)x - (14)/(3) = -(1)/(8)x^2 +4x`

Multiply through by 24

`16x- 112 = -3x^2 +96x`

Express as:

`3x^2 + 16x -96x- 112 = 0`

`3x^2 -80x- 112 = 0`

Using a calculator:

`x = 28` or
`x = -(4)/(3)`

x can not be negative:

So:

`x = 28`

Substitute
`x = 28` in
`y = -(1)/(8)x^2 +4x` to calculate the height it landed

`y = -(1)/(8) * 28^2 + 4 * 28`

`y = 14`