3c^2+18c+15=0

Solution for 3c^2+18c+15=0 equation:

Simplifying
3c2 + 18c + 15 = 0

Reorder the terms:
15 + 18c + 3c2 = 0

Solving
15 + 18c + 3c2 = 0

Solving for variable 'c'.

Factor out the Greatest Common Factor (GCF), '3'.
3(5 + 6c + c2) = 0

Factor a trinomial.
3((5 + c)(1 + c)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(5 + c)' equal to zero and attempt to solve:

Simplifying
5 + c = 0

Solving
5 + c = 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 + c = 0 + -5

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

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

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

Simplifying
1 + c = 0

Solving
1 + c = 0

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

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

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

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

Simplifying
c = -1
Solution
c = {-5, -1}