Solve the equation x2 − 100 = 0. x = 0, -10 x = 0, 10 x = 10, -10 x = 50, -50

(x² - 100) = 0 is a difference of two squares. If you factor it, you get (x - 10)(x + 10) = 0

Set each equation equal to zero.

x - 10 = 0
x = 0 + 10
x = 10

x + 10 = 0
x = 0 - 10
x = - 10

So x = - 10, 10. Your third option is your answer.