5u^2-20=0

Solution for 5u^2-20=0 equation:

Simplifying
5u2 + -20 = 0

Reorder the terms:
-20 + 5u2 = 0

Solving
-20 + 5u2 = 0

Solving for variable 'u'.

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

Add '20' to each side of the equation.
-20 + 20 + 5u2 = 0 + 20

Combine like terms: -20 + 20 = 0
0 + 5u2 = 0 + 20
5u2 = 0 + 20

Combine like terms: 0 + 20 = 20
5u2 = 20

Divide each side by '5'.
u2 = 4

Simplifying
u2 = 4

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