(b-9)(b+8)=0

Solution for (b-9)(b+8)=0 equation:

Simplifying
(b + -9)(b + 8) = 0

Reorder the terms:
(-9 + b)(b + 8) = 0

Reorder the terms:
(-9 + b)(8 + b) = 0

Multiply (-9 + b) * (8 + b)
(-9(8 + b) + b(8 + b)) = 0
((8 * -9 + b * -9) + b(8 + b)) = 0
((-72 + -9b) + b(8 + b)) = 0
(-72 + -9b + (8 * b + b * b)) = 0
(-72 + -9b + (8b + b2)) = 0

Combine like terms: -9b + 8b = -1b
(-72 + -1b + b2) = 0

Solving
-72 + -1b + b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-8 + -1b)(9 + -1b) = 0

Subproblem 1
Set the factor '(-8 + -1b)' equal to zero and attempt to solve:

Simplifying
-8 + -1b = 0

Solving
-8 + -1b = 0

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

Add '8' to each side of the equation.
-8 + 8 + -1b = 0 + 8

Combine like terms: -8 + 8 = 0
0 + -1b = 0 + 8
-1b = 0 + 8

Combine like terms: 0 + 8 = 8
-1b = 8

Divide each side by '-1'.
b = -8

Simplifying
b = -8
Subproblem 2
Set the factor '(9 + -1b)' equal to zero and attempt to solve:

Simplifying
9 + -1b = 0

Solving
9 + -1b = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1b = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1b = 0 + -9
-1b = 0 + -9

Combine like terms: 0 + -9 = -9
-1b = -9

Divide each side by '-1'.
b = 9

Simplifying
b = 9
Solution
b = {-8, 9}