0=(28c^2)-72c-36

Solution for 0=(28c^2)-72c-36 equation:

Simplifying
0 = (28c2) + -72c + -36

Reorder the terms:
0 = -36 + -72c + (28c2)

Solving
0 = -36 + -72c + (28c2)

Solving for variable 'c'.

Combine like terms: 0 + 36 = 36
36 + 72c + (-28c2) = -36 + -72c + (28c2) + 36 + 72c + (-28c2)

Reorder the terms:
36 + 72c + (-28c2) = -36 + 36 + -72c + 72c + (28c2) + (-28c2)

Combine like terms: -36 + 36 = 0
36 + 72c + (-28c2) = 0 + -72c + 72c + (28c2) + (-28c2)
36 + 72c + (-28c2) = -72c + 72c + (28c2) + (-28c2)

Combine like terms: -72c + 72c = 0
36 + 72c + (-28c2) = 0 + (28c2) + (-28c2)
36 + 72c + (-28c2) = (28c2) + (-28c2)

Combine like terms: (28c2) + (-28c2) = 0
36 + 72c + (-28c2) = 0

Factor out the Greatest Common Factor (GCF), '4'.
4(9 + 18c + (-7c2)) = 0

Factor a trinomial.
4((3 + -1c)(3 + 7c)) = 0

Ignore the factor 4.
Subproblem 1
Set the factor '(3 + -1c)' equal to zero and attempt to solve:

Simplifying
3 + -1c = 0

Solving
3 + -1c = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1c = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1c = 0 + -3
-1c = 0 + -3

Combine like terms: 0 + -3 = -3
-1c = -3

Divide each side by '-1'.
c = 3

Simplifying
c = 3
Subproblem 2
Set the factor '(3 + 7c)' equal to zero and attempt to solve:

Simplifying
3 + 7c = 0

Solving
3 + 7c = 0

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

Add '-3' to each side of the equation.
3 + -3 + 7c = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 7c = 0 + -3
7c = 0 + -3

Combine like terms: 0 + -3 = -3
7c = -3

Divide each side by '7'.
c = -0.4285714286

Simplifying
c = -0.4285714286
Solution
c = {3, -0.4285714286}