b^2+9b=-18

Solution for b^2+9b=-18 equation:

Simplifying
b2 + 9b = -18

Reorder the terms:
9b + b2 = -18

Solving
9b + b2 = -18

Solving for variable 'b'.

Reorder the terms:
18 + 9b + b2 = -18 + 18

Combine like terms: -18 + 18 = 0
18 + 9b + b2 = 0

Factor a trinomial.
(6 + b)(3 + b) = 0

Subproblem 1
Set the factor '(6 + b)' equal to zero and attempt to solve:

Simplifying
6 + b = 0

Solving
6 + b = 0

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

Add '-6' to each side of the equation.
6 + -6 + b = 0 + -6

Combine like terms: 6 + -6 = 0
0 + b = 0 + -6
b = 0 + -6

Combine like terms: 0 + -6 = -6
b = -6

Simplifying
b = -6
Subproblem 2
Set the factor '(3 + b)' equal to zero and attempt to solve:

Simplifying
3 + b = 0

Solving
3 + b = 0

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

Add '-3' to each side of the equation.
3 + -3 + b = 0 + -3

Combine like terms: 3 + -3 = 0
0 + b = 0 + -3
b = 0 + -3

Combine like terms: 0 + -3 = -3
b = -3

Simplifying
b = -3
Solution
b = {-6, -3}