(b+5)(b-9)=0

Solution for (b+5)(b-9)=0 equation:

Simplifying
(b + 5)(b + -9) = 0

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

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

Multiply (5 + b) * (-9 + b)
(5(-9 + b) + b(-9 + b)) = 0
((-9 * 5 + b * 5) + b(-9 + b)) = 0
((-45 + 5b) + b(-9 + b)) = 0
(-45 + 5b + (-9 * b + b * b)) = 0
(-45 + 5b + (-9b + b2)) = 0

Combine like terms: 5b + -9b = -4b
(-45 + -4b + b2) = 0

Solving
-45 + -4b + b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-5 + -1b)(9 + -1b) = 0

Subproblem 1
Set the factor '(-5 + -1b)' equal to zero and attempt to solve:

Simplifying
-5 + -1b = 0

Solving
-5 + -1b = 0

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

Add '5' to each side of the equation.
-5 + 5 + -1b = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1b = 0 + 5
-1b = 0 + 5

Combine like terms: 0 + 5 = 5
-1b = 5

Divide each side by '-1'.
b = -5

Simplifying
b = -5
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 = {-5, 9}