0=u^2-20

Solution for 0=u^2-20 equation:

Simplifying
0 = u2 + -20

Reorder the terms:
0 = -20 + u2

Solving
0 = -20 + u2

Solving for variable 'u'.

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

Add '-1u2' to each side of the equation.
0 + -1u2 = -20 + u2 + -1u2
Remove the zero:
-1u2 = -20 + u2 + -1u2

Combine like terms: u2 + -1u2 = 0
-1u2 = -20 + 0
-1u2 = -20

Divide each side by '-1'.
u2 = 20

Simplifying
u2 = 20

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