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 path h(x)=−x2+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: 0=−x2+15x . How far will the firework travel before it reaches the ground?(1 point)
Responses

7.5 feet
7.5 feet

30 feet
30 feet

−15 feet
negative 15 feet

15 feet
15 feet
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Answer 1

To find out how far the firework will travel before it reaches the ground, we need to solve the equation \(0 = -x^2 + 15x\).

First, let's rearrange the equation:

\[
-x^2 + 15x = 0
\]

Now, we can factor out \(x\):

\[
x(-x + 15) = 0
\]

This gives us two possible solutions:

1. \(x = 0\)
2. \(-x + 15 = 0\) which simplifies to \(x = 15\)

The solution \(x = 0\) corresponds to the time when the firework is launched, and \(x = 15\) is when it reaches the ground.

Thus, the firework will travel **15 feet** before it reaches the ground.

So the correct response is:

**15 feet**.