4r^2-80=0

Solution for 4r^2-80=0 equation:

Simplifying
4r2 + -80 = 0

Reorder the terms:
-80 + 4r2 = 0

Solving
-80 + 4r2 = 0

Solving for variable 'r'.

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

Add '80' to each side of the equation.
-80 + 80 + 4r2 = 0 + 80

Combine like terms: -80 + 80 = 0
0 + 4r2 = 0 + 80
4r2 = 0 + 80

Combine like terms: 0 + 80 = 80
4r2 = 80

Divide each side by '4'.
r2 = 20

Simplifying
r2 = 20

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