Solve the quadratic equation by factorization.
First, move 625 to the left side.
x² = 625
x² - 625 = 0
Second, factorize the terms.
Remember that a² - b² = (a + b)(a - b)
x² - 625 = 0
(x + 25)(x - 25) = 0
The zeros of the equation are
⇒ x + 25 = 0
x = -25
or
⇒ x - 25 = 0
x = 25
The answers are option b and option c