Question

What are the solutions to the equation x² = 625?
Select EACH correct answer.
A. -312.5
B.-25
C.25
D. 312.5

Answer 1

$x = \sqrt{625 }$
$x = 25$
the answer is C

Answer 2

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