(ab+3)(ab-3)=0

Solution for (ab+3)(ab-3)=0 equation:

Simplifying
(ab + 3)(ab + -3) = 0

Reorder the terms:
(3 + ab)(ab + -3) = 0

Reorder the terms:
(3 + ab)(-3 + ab) = 0

Multiply (3 + ab) * (-3 + ab)
(3(-3 + ab) + ab(-3 + ab)) = 0
((-3 * 3 + ab * 3) + ab(-3 + ab)) = 0
((-9 + 3ab) + ab(-3 + ab)) = 0
(-9 + 3ab + (-3 * ab + ab * ab)) = 0
(-9 + 3ab + (-3ab + a2b2)) = 0

Combine like terms: 3ab + -3ab = 0
(-9 + 0 + a2b2) = 0
(-9 + a2b2) = 0

Solving
-9 + a2b2 = 0

Solving for variable 'a'.

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

Add '9' to each side of the equation.
-9 + 9 + a2b2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + a2b2 = 0 + 9
a2b2 = 0 + 9

Combine like terms: 0 + 9 = 9
a2b2 = 9

Divide each side by 'b2'.
a2 = 9b-2

Simplifying
a2 = 9b-2

Take the square root of each side:
a = {-3b-1, 3b-1}