To use the Zero Product Property, Leon should solve the equation by setting each factor in the equation \( 0 = -\frac{1}{2}x(x - 20) \) equal to zero. This leads to two equations:
- \(-\frac{1}{2}x = 0\)
- \(x - 20 = 0\)
Solving these:
- \(-\frac{1}{2}x = 0\) gives \(x = 0\).
- \(x - 20 = 0\) gives \(x = 20\).
Therefore, the ball hits the ground (height equals 0) when \(x = 0\) (the starting point) and \(x = 20\) (the point where it lands).
So the best response is: Solve the two equations: \(-\frac{1}{2}x = 0\) and \(x - 20 = 0\).