y*y+-20=0

Solution for y*y+-20=0 equation:

Simplifying
y * y + -20 = 0

Multiply y * y
y2 + -20 = 0

Reorder the terms:
-20 + y2 = 0

Solving
-20 + y2 = 0

Solving for variable 'y'.

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

Add '20' to each side of the equation.
-20 + 20 + y2 = 0 + 20

Combine like terms: -20 + 20 = 0
0 + y2 = 0 + 20
y2 = 0 + 20

Combine like terms: 0 + 20 = 20
y2 = 20

Simplifying
y2 = 20

Take the square root of each side:
y = {-4.472135955, 4.472135955}