0=x^2-20

Solution for 0=x^2-20 equation:

Simplifying
0 = x2 + -20

Reorder the terms:
0 = -20 + x2

Solving
0 = -20 + x2

Solving for variable 'x'.

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

Add '-1x2' to each side of the equation.
0 + -1x2 = -20 + x2 + -1x2
Remove the zero:
-1x2 = -20 + x2 + -1x2

Combine like terms: x2 + -1x2 = 0
-1x2 = -20 + 0
-1x2 = -20

Divide each side by '-1'.
x2 = 20

Simplifying
x2 = 20

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