20c^2-13cr-15r^2=

Solution for 20c^2-13cr-15r^2= equation:

Simplifying
20c2 + -13cr + -15r2 = 0

Reorder the terms:
-13cr + 20c2 + -15r2 = 0

Solving
-13cr + 20c2 + -15r2 = 0

Solving for variable 'c'.

Factor a trinomial.
(4c + -5r)(5c + 3r) = 0

Subproblem 1
Set the factor '(4c + -5r)' equal to zero and attempt to solve:

Simplifying
4c + -5r = 0

Solving
4c + -5r = 0

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

Add '5r' to each side of the equation.
4c + -5r + 5r = 0 + 5r

Combine like terms: -5r + 5r = 0
4c + 0 = 0 + 5r
4c = 0 + 5r
Remove the zero:
4c = 5r

Divide each side by '4'.
c = 1.25r

Simplifying
c = 1.25r
Subproblem 2
Set the factor '(5c + 3r)' equal to zero and attempt to solve:

Simplifying
5c + 3r = 0

Solving
5c + 3r = 0

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

Add '-3r' to each side of the equation.
5c + 3r + -3r = 0 + -3r

Combine like terms: 3r + -3r = 0
5c + 0 = 0 + -3r
5c = 0 + -3r
Remove the zero:
5c = -3r

Divide each side by '5'.
c = -0.6r

Simplifying
c = -0.6r
Solution
c = {1.25r, -0.6r}