=(3c+6)(3c-6)

Solution for =(3c+6)(3c-6) equation:

Simplifying
0 = (3c + 6)(3c + -6)

Reorder the terms:
0 = (6 + 3c)(3c + -6)

Reorder the terms:
0 = (6 + 3c)(-6 + 3c)

Multiply (6 + 3c) * (-6 + 3c)
0 = (6(-6 + 3c) + 3c * (-6 + 3c))
0 = ((-6 * 6 + 3c * 6) + 3c * (-6 + 3c))
0 = ((-36 + 18c) + 3c * (-6 + 3c))
0 = (-36 + 18c + (-6 * 3c + 3c * 3c))
0 = (-36 + 18c + (-18c + 9c2))

Combine like terms: 18c + -18c = 0
0 = (-36 + 0 + 9c2)
0 = (-36 + 9c2)

Solving
0 = -36 + 9c2

Solving for variable 'c'.

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

Add '-9c2' to each side of the equation.
0 + -9c2 = -36 + 9c2 + -9c2
Remove the zero:
-9c2 = -36 + 9c2 + -9c2

Combine like terms: 9c2 + -9c2 = 0
-9c2 = -36 + 0
-9c2 = -36

Divide each side by '-9'.
c2 = 4

Simplifying
c2 = 4

Take the square root of each side:
c = {-2, 2}