Question

What are the solution(s) of x2-4=0

Answer 1

Is that x^2 -4 = 0?
Then the two solutions are x = 2 and x = -2

Answer 2

First you add 4 on both sides
X^2=0
Then you take square on both sides
X=+- the square root of 4
Simplify that
X=plus or minus 2

The answer can be either -2 or +2 (which is just 2)