5r^2=20r

Solution for 5r^2=20r equation:

Simplifying
5r2 = 20r

Solving
5r2 = 20r

Solving for variable 'r'.

Reorder the terms:
-20r + 5r2 = 20r + -20r

Combine like terms: 20r + -20r = 0
-20r + 5r2 = 0

Factor out the Greatest Common Factor (GCF), '5r'.
5r(-4 + r) = 0

Ignore the factor 5.
Subproblem 1
Set the factor 'r' equal to zero and attempt to solve:

Simplifying
r = 0

Solving
r = 0

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

Simplifying
r = 0
Subproblem 2
Set the factor '(-4 + r)' equal to zero and attempt to solve:

Simplifying
-4 + r = 0

Solving
-4 + r = 0

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

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

Combine like terms: -4 + 4 = 0
0 + r = 0 + 4
r = 0 + 4

Combine like terms: 0 + 4 = 4
r = 4

Simplifying
r = 4
Solution
r = {0, 4}