Question

Why does every positive number have 2 square roots?

Answer 1

because they all have a negative and a positive part to it 

Answer 2

When you take the sqrt of 4 the answers are -2 and +2.
This is because if we take 2 square it, (2)^2, we get 4.
The same is true for -2.
(-2)^2 = 4 because -2 * -2 = +4