(2a+6)(2a-6)=

Solution for (2a+6)(2a-6)= equation:

Simplifying
(2a + 6)(2a + -6) = 0

Reorder the terms:
(6 + 2a)(2a + -6) = 0

Reorder the terms:
(6 + 2a)(-6 + 2a) = 0

Multiply (6 + 2a) * (-6 + 2a)
(6(-6 + 2a) + 2a * (-6 + 2a)) = 0
((-6 * 6 + 2a * 6) + 2a * (-6 + 2a)) = 0
((-36 + 12a) + 2a * (-6 + 2a)) = 0
(-36 + 12a + (-6 * 2a + 2a * 2a)) = 0
(-36 + 12a + (-12a + 4a2)) = 0

Combine like terms: 12a + -12a = 0
(-36 + 0 + 4a2) = 0
(-36 + 4a2) = 0

Solving
-36 + 4a2 = 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 + 4a2 = 0 + 36

Combine like terms: -36 + 36 = 0
0 + 4a2 = 0 + 36
4a2 = 0 + 36

Combine like terms: 0 + 36 = 36
4a2 = 36

Divide each side by '4'.
a2 = 9

Simplifying
a2 = 9

Take the square root of each side:
a = {-3, 3}