x = 20 and x = -5
Explanation:
x² – 15x – 100 = 0
First, find factors that multiply to get -100 and add to -15.
These factors are -20 and 5.
So we have (x - 20)(x + 5) = 0.
Now use the zero product property to get x - 20 = 0 or x + 5 = 0.
Solving from here, we get x = 20 or x = -5.