Question

As Isla prepares to set off fireworks, she wants to ensure the spectators are a safe distance away.
When shot in the air, one firework will follow the pathh (x) = -x^2 + 15x, where h(x) is the height
of the firework, and x is the horizontal distance it travels in feet. To determine how far the firework will travel before it reaches the ground, Isla sets the height equal to zero, and solves the following quadratic equation: O = -x^2 + 15x. How far will the firework travel before it reaches the ground?
(1 point)
15 feet
30 feet
7.5 feet
-15 feet

Answer 1

15 feet

Solve 0 = -x^2 + 15x → x(-x + 15) = 0, so x = 0 (launch point) or x = 15 ft (where it hits the ground).