(b+3)(2b-6)=0

Solution for (b+3)(2b-6)=0 equation:

Simplifying
(b + 3)(2b + -6) = 0

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

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

Multiply (3 + b) * (-6 + 2b)
(3(-6 + 2b) + b(-6 + 2b)) = 0
((-6 * 3 + 2b * 3) + b(-6 + 2b)) = 0
((-18 + 6b) + b(-6 + 2b)) = 0
(-18 + 6b + (-6 * b + 2b * b)) = 0
(-18 + 6b + (-6b + 2b2)) = 0

Combine like terms: 6b + -6b = 0
(-18 + 0 + 2b2) = 0
(-18 + 2b2) = 0

Solving
-18 + 2b2 = 0

Solving for variable 'b'.

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

Add '18' to each side of the equation.
-18 + 18 + 2b2 = 0 + 18

Combine like terms: -18 + 18 = 0
0 + 2b2 = 0 + 18
2b2 = 0 + 18

Combine like terms: 0 + 18 = 18
2b2 = 18

Divide each side by '2'.
b2 = 9

Simplifying
b2 = 9

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