-b^2+b+72=0

Solution for -b^2+b+72=0 equation:

Simplifying
-1b2 + b + 72 = 0

Reorder the terms:
72 + b + -1b2 = 0

Solving
72 + b + -1b2 = 0

Solving for variable 'b'.

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

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

Simplifying
8 + b = 0

Solving
8 + b = 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 + b = 0 + -8

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

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

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