b^2-9b=36

Solution for b^2-9b=36 equation:

Simplifying
b2 + -9b = 36

Reorder the terms:
-9b + b2 = 36

Solving
-9b + b2 = 36

Solving for variable 'b'.

Reorder the terms:
-36 + -9b + b2 = 36 + -36

Combine like terms: 36 + -36 = 0
-36 + -9b + b2 = 0

Factor a trinomial.
(-3 + -1b)(12 + -1b) = 0

Subproblem 1
Set the factor '(-3 + -1b)' equal to zero and attempt to solve:

Simplifying
-3 + -1b = 0

Solving
-3 + -1b = 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 + -1b = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -1b = 0 + 3
-1b = 0 + 3

Combine like terms: 0 + 3 = 3
-1b = 3

Divide each side by '-1'.
b = -3

Simplifying
b = -3
Subproblem 2
Set the factor '(12 + -1b)' equal to zero and attempt to solve:

Simplifying
12 + -1b = 0

Solving
12 + -1b = 0

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

Add '-12' to each side of the equation.
12 + -12 + -1b = 0 + -12

Combine like terms: 12 + -12 = 0
0 + -1b = 0 + -12
-1b = 0 + -12

Combine like terms: 0 + -12 = -12
-1b = -12

Divide each side by '-1'.
b = 12

Simplifying
b = 12
Solution
b = {-3, 12}