(b+5)(b-18)=0

Solution for (b+5)(b-18)=0 equation:

Simplifying
(b + 5)(b + -18) = 0

Reorder the terms:
(5 + b)(b + -18) = 0

Reorder the terms:
(5 + b)(-18 + b) = 0

Multiply (5 + b) * (-18 + b)
(5(-18 + b) + b(-18 + b)) = 0
((-18 * 5 + b * 5) + b(-18 + b)) = 0
((-90 + 5b) + b(-18 + b)) = 0
(-90 + 5b + (-18 * b + b * b)) = 0
(-90 + 5b + (-18b + b2)) = 0

Combine like terms: 5b + -18b = -13b
(-90 + -13b + b2) = 0

Solving
-90 + -13b + b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-5 + -1b)(18 + -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 '(18 + -1b)' equal to zero and attempt to solve:

Simplifying
18 + -1b = 0

Solving
18 + -1b = 0

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

Add '-18' to each side of the equation.
18 + -18 + -1b = 0 + -18

Combine like terms: 18 + -18 = 0
0 + -1b = 0 + -18
-1b = 0 + -18

Combine like terms: 0 + -18 = -18
-1b = -18

Divide each side by '-1'.
b = 18

Simplifying
b = 18
Solution
b = {-5, 18}