(3a+6)(3a-6)=0

Solution for (3a+6)(3a-6)=0 equation:

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

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

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

Multiply (6 + 3a) * (-6 + 3a)
(6(-6 + 3a) + 3a * (-6 + 3a)) = 0
((-6 * 6 + 3a * 6) + 3a * (-6 + 3a)) = 0
((-36 + 18a) + 3a * (-6 + 3a)) = 0
(-36 + 18a + (-6 * 3a + 3a * 3a)) = 0
(-36 + 18a + (-18a + 9a2)) = 0

Combine like terms: 18a + -18a = 0
(-36 + 0 + 9a2) = 0
(-36 + 9a2) = 0

Solving
-36 + 9a2 = 0

Solving for variable 'a'.

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

Add '36' to each side of the equation.
-36 + 36 + 9a2 = 0 + 36

Combine like terms: -36 + 36 = 0
0 + 9a2 = 0 + 36
9a2 = 0 + 36

Combine like terms: 0 + 36 = 36
9a2 = 36

Divide each side by '9'.
a2 = 4

Simplifying
a2 = 4

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