For this case, the first thing you should do is rewrite the expression:
x ^ 2 = 4
We clear x to find the points described by the expression:
x = + / - root (4)
x = + / - 2
Therefore, the points sought are:
x1 = 2
x2 = -2
Answer:
x1 = 2
x2 = -2
Note: see attached image