(3a-9b)(3a+9b)=

Solution for (3a-9b)(3a+9b)= equation:

Simplifying
(3a + -9b)(3a + 9b) = 0

Multiply (3a + -9b) * (3a + 9b)
(3a * (3a + 9b) + -9b * (3a + 9b)) = 0
((3a * 3a + 9b * 3a) + -9b * (3a + 9b)) = 0

Reorder the terms:
((27ab + 9a2) + -9b * (3a + 9b)) = 0
((27ab + 9a2) + -9b * (3a + 9b)) = 0
(27ab + 9a2 + (3a * -9b + 9b * -9b)) = 0
(27ab + 9a2 + (-27ab + -81b2)) = 0

Reorder the terms:
(27ab + -27ab + 9a2 + -81b2) = 0

Combine like terms: 27ab + -27ab = 0
(0 + 9a2 + -81b2) = 0
(9a2 + -81b2) = 0

Solving
9a2 + -81b2 = 0

Solving for variable 'a'.

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

Add '81b2' to each side of the equation.
9a2 + -81b2 + 81b2 = 0 + 81b2

Combine like terms: -81b2 + 81b2 = 0
9a2 + 0 = 0 + 81b2
9a2 = 0 + 81b2
Remove the zero:
9a2 = 81b2

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

Simplifying
a2 = 9b2

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