125r^2-0r-20=0

Solution for 125r^2-0r-20=0 equation:

Simplifying
125r2 + 0r + -20 = 0

Anything times zero is zero.
125r2 + 0r + -20 = 0

Reorder the terms:
0 + -20 + 125r2 = 0

Combine like terms: 0 + -20 = -20
-20 + 125r2 = 0

Solving
-20 + 125r2 = 0

Solving for variable 'r'.

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

Add '20' to each side of the equation.
-20 + 20 + 125r2 = 0 + 20

Combine like terms: -20 + 20 = 0
0 + 125r2 = 0 + 20
125r2 = 0 + 20

Combine like terms: 0 + 20 = 20
125r2 = 20

Divide each side by '125'.
r2 = 0.16

Simplifying
r2 = 0.16

Take the square root of each side:
r = {-0.4, 0.4}