(b-3)(b+3)=12

Solution for (b-3)(b+3)=12 equation:

Simplifying
(b + -3)(b + 3) = 12

Reorder the terms:
(-3 + b)(b + 3) = 12

Reorder the terms:
(-3 + b)(3 + b) = 12

Multiply (-3 + b) * (3 + b)
(-3(3 + b) + b(3 + b)) = 12
((3 * -3 + b * -3) + b(3 + b)) = 12
((-9 + -3b) + b(3 + b)) = 12
(-9 + -3b + (3 * b + b * b)) = 12
(-9 + -3b + (3b + b2)) = 12

Combine like terms: -3b + 3b = 0
(-9 + 0 + b2) = 12
(-9 + b2) = 12

Solving
-9 + b2 = 12

Solving for variable 'b'.

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

Add '9' to each side of the equation.
-9 + 9 + b2 = 12 + 9

Combine like terms: -9 + 9 = 0
0 + b2 = 12 + 9
b2 = 12 + 9

Combine like terms: 12 + 9 = 21
b2 = 21

Simplifying
b2 = 21

Take the square root of each side:
b = {-4.582575695, 4.582575695}