Question

How do you do this problem?
Solve by factoring or finding square roots.
x^2-1=0

Answer 1

x² - 1 = 0
+ 1 + 1
x² = 1
x = +1

Answer 2

use formula^: a²-b²= (a-b)(a+b)
x²-1=0
x²-1²=0
(x-1)(x+1)=0
x-1=0⇒ x₁=-1
x+1=0 ⇒x₂=1
Answer: x=+-1