(6c+9)(6c-9)=

Solution for (6c+9)(6c-9)= equation:

Simplifying
(6c + 9)(6c + -9) = 0

Reorder the terms:
(9 + 6c)(6c + -9) = 0

Reorder the terms:
(9 + 6c)(-9 + 6c) = 0

Multiply (9 + 6c) * (-9 + 6c)
(9(-9 + 6c) + 6c * (-9 + 6c)) = 0
((-9 * 9 + 6c * 9) + 6c * (-9 + 6c)) = 0
((-81 + 54c) + 6c * (-9 + 6c)) = 0
(-81 + 54c + (-9 * 6c + 6c * 6c)) = 0
(-81 + 54c + (-54c + 36c2)) = 0

Combine like terms: 54c + -54c = 0
(-81 + 0 + 36c2) = 0
(-81 + 36c2) = 0

Solving
-81 + 36c2 = 0

Solving for variable 'c'.

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

Add '81' to each side of the equation.
-81 + 81 + 36c2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + 36c2 = 0 + 81
36c2 = 0 + 81

Combine like terms: 0 + 81 = 81
36c2 = 81

Divide each side by '36'.
c2 = 2.25

Simplifying
c2 = 2.25

Take the square root of each side:
c = {-1.5, 1.5}