-2c(-c-12)=-2c-12

Solution for -2c(-c-12)=-2c-12 equation:

Simplifying
-2c(-1c + -12) = -2c + -12

Reorder the terms:
-2c(-12 + -1c) = -2c + -12
(-12 * -2c + -1c * -2c) = -2c + -12
(24c + 2c2) = -2c + -12

Reorder the terms:
24c + 2c2 = -12 + -2c

Solving
24c + 2c2 = -12 + -2c

Solving for variable 'c'.

Reorder the terms:
12 + 24c + 2c + 2c2 = -12 + -2c + 12 + 2c

Combine like terms: 24c + 2c = 26c
12 + 26c + 2c2 = -12 + -2c + 12 + 2c

Reorder the terms:
12 + 26c + 2c2 = -12 + 12 + -2c + 2c

Combine like terms: -12 + 12 = 0
12 + 26c + 2c2 = 0 + -2c + 2c
12 + 26c + 2c2 = -2c + 2c

Combine like terms: -2c + 2c = 0
12 + 26c + 2c2 = 0

Factor out the Greatest Common Factor (GCF), '2'.
2(6 + 13c + c2) = 0

Ignore the factor 2.
Subproblem 1
Set the factor '(6 + 13c + c2)' equal to zero and attempt to solve:

Simplifying
6 + 13c + c2 = 0

Solving
6 + 13c + c2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-6' to each side of the equation.
6 + 13c + -6 + c2 = 0 + -6

Reorder the terms:
6 + -6 + 13c + c2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + 13c + c2 = 0 + -6
13c + c2 = 0 + -6

Combine like terms: 0 + -6 = -6
13c + c2 = -6

The c term is 13c.  Take half its coefficient (6.5).
Square it (42.25) and add it to both sides.

Add '42.25' to each side of the equation.
13c + 42.25 + c2 = -6 + 42.25

Reorder the terms:
42.25 + 13c + c2 = -6 + 42.25

Combine like terms: -6 + 42.25 = 36.25
42.25 + 13c + c2 = 36.25

Factor a perfect square on the left side:
(c + 6.5)(c + 6.5) = 36.25

Calculate the square root of the right side: 6.020797289

Break this problem into two subproblems by setting 
(c + 6.5) equal to 6.020797289 and -6.020797289.

Subproblem 1
c + 6.5 = 6.020797289

Simplifying
c + 6.5 = 6.020797289

Reorder the terms:
6.5 + c = 6.020797289

Solving
6.5 + c = 6.020797289

Solving for variable 'c'.

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

Add '-6.5' to each side of the equation.
6.5 + -6.5 + c = 6.020797289 + -6.5

Combine like terms: 6.5 + -6.5 = 0.0
0.0 + c = 6.020797289 + -6.5
c = 6.020797289 + -6.5

Combine like terms: 6.020797289 + -6.5 = -0.479202711
c = -0.479202711

Simplifying
c = -0.479202711

Subproblem 2
c + 6.5 = -6.020797289

Simplifying
c + 6.5 = -6.020797289

Reorder the terms:
6.5 + c = -6.020797289

Solving
6.5 + c = -6.020797289

Solving for variable 'c'.

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

Add '-6.5' to each side of the equation.
6.5 + -6.5 + c = -6.020797289 + -6.5

Combine like terms: 6.5 + -6.5 = 0.0
0.0 + c = -6.020797289 + -6.5
c = -6.020797289 + -6.5

Combine like terms: -6.020797289 + -6.5 = -12.520797289
c = -12.520797289

Simplifying
c = -12.520797289

Solution
The solution to the problem is based on the solutions
from the subproblems.
c = {-0.479202711, -12.520797289}
Solution
c = {-0.479202711, -12.520797289}