4=y*y

Solution for 4=y*y equation:

Simplifying
4 = y * y

Multiply y * y
4 = y2

Solving
4 = y2

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-1y2' to each side of the equation.
4 + -1y2 = y2 + -1y2

Combine like terms: y2 + -1y2 = 0
4 + -1y2 = 0

Add '-4' to each side of the equation.
4 + -4 + -1y2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1y2 = 0 + -4
-1y2 = 0 + -4

Combine like terms: 0 + -4 = -4
-1y2 = -4

Divide each side by '-1'.
y2 = 4

Simplifying
y2 = 4

Take the square root of each side:
y = {-2, 2}