Question

Solve x^2 - 9 = 0

x = 3

no real solution

x = 3, -3

x = -3

Answer 1

add9 to both sides, then take the square root of both sides. the answer is x=3

Answer 2

keep in mind that if you have x^2 = 9, it would be x = 3 or x = -3

Answer 3

another way to do it

x^2 - 9 = 0

(x-3)(x+3) = 0

x-3=0 or x+3=0

x = 3 or x = -3