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

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

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

Multiply (2a + 6b) * (2a + -6b)
0 = (2a * (2a + -6b) + 6b * (2a + -6b))
0 = ((2a * 2a + -6b * 2a) + 6b * (2a + -6b))

Reorder the terms:
0 = ((-12ab + 4a2) + 6b * (2a + -6b))
0 = ((-12ab + 4a2) + 6b * (2a + -6b))
0 = (-12ab + 4a2 + (2a * 6b + -6b * 6b))
0 = (-12ab + 4a2 + (12ab + -36b2))

Reorder the terms:
0 = (-12ab + 12ab + 4a2 + -36b2)

Combine like terms: -12ab + 12ab = 0
0 = (0 + 4a2 + -36b2)
0 = (4a2 + -36b2)

Solving
0 = 4a2 + -36b2

Solving for variable 'a'.

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

Add '-4a2' to each side of the equation.
0 + -4a2 = 4a2 + -4a2 + -36b2
Remove the zero:
-4a2 = 4a2 + -4a2 + -36b2

Combine like terms: 4a2 + -4a2 = 0
-4a2 = 0 + -36b2
-4a2 = -36b2

Divide each side by '-4'.
a2 = 9b2

Simplifying
a2 = 9b2

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