To determine how far the firework will travel before it reaches the ground, we need to solve the quadratic equation \(0 = -x^2 + 15x\).
Let's start by rearranging the equation:
\[ -x^2 + 15x = 0 \]
We can factor out \(x\):
\[ x(-x + 15) = 0 \]
Now we can set each factor equal to zero:
- \(x = 0\)
- \(-x + 15 = 0\) which gives us \(x = 15\)
These roots indicate that the firework reaches the ground at \(x = 0\) feet (the launch point) and \(x = 15\) feet (the point of landing).
Thus, the firework will travel 15 feet before it reaches the ground.
The correct response is:
15 feet.