(4c-20)(3c+18)=0

Solution for (4c-20)(3c+18)=0 equation:

Simplifying
(4c + -20)(3c + 18) = 0

Reorder the terms:
(-20 + 4c)(3c + 18) = 0

Reorder the terms:
(-20 + 4c)(18 + 3c) = 0

Multiply (-20 + 4c) * (18 + 3c)
(-20(18 + 3c) + 4c * (18 + 3c)) = 0
((18 * -20 + 3c * -20) + 4c * (18 + 3c)) = 0
((-360 + -60c) + 4c * (18 + 3c)) = 0
(-360 + -60c + (18 * 4c + 3c * 4c)) = 0
(-360 + -60c + (72c + 12c2)) = 0

Combine like terms: -60c + 72c = 12c
(-360 + 12c + 12c2) = 0

Solving
-360 + 12c + 12c2 = 0

Solving for variable 'c'.

Factor out the Greatest Common Factor (GCF), '12'.
12(-30 + c + c2) = 0

Factor a trinomial.
12((-6 + -1c)(5 + -1c)) = 0

Ignore the factor 12.
Subproblem 1
Set the factor '(-6 + -1c)' equal to zero and attempt to solve:

Simplifying
-6 + -1c = 0

Solving
-6 + -1c = 0

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

Add '6' to each side of the equation.
-6 + 6 + -1c = 0 + 6

Combine like terms: -6 + 6 = 0
0 + -1c = 0 + 6
-1c = 0 + 6

Combine like terms: 0 + 6 = 6
-1c = 6

Divide each side by '-1'.
c = -6

Simplifying
c = -6
Subproblem 2
Set the factor '(5 + -1c)' equal to zero and attempt to solve:

Simplifying
5 + -1c = 0

Solving
5 + -1c = 0

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

Add '-5' to each side of the equation.
5 + -5 + -1c = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -1c = 0 + -5
-1c = 0 + -5

Combine like terms: 0 + -5 = -5
-1c = -5

Divide each side by '-1'.
c = 5

Simplifying
c = 5
Solution
c = {-6, 5}