Question

Use the quadratic formula to solve x2 – 4 = 0.
x = -2 or x = 2 x = -2 or x = 4
x = 2 or x = -4 x = -4 or x = -2

Answer 1

it factors into
(x+2)(x-2)
by some rule.
set it to 0 and solve.
(x+2)(x-2)=0
x=2, -2