b^2+5b-84=0

Solution for b^2+5b-84=0 equation:

Simplifying
b2 + 5b + -84 = 0

Reorder the terms:
-84 + 5b + b2 = 0

Solving
-84 + 5b + b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-12 + -1b)(7 + -1b) = 0

Subproblem 1
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
Subproblem 2
Set the factor '(7 + -1b)' equal to zero and attempt to solve:

Simplifying
7 + -1b = 0

Solving
7 + -1b = 0

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

Add '-7' to each side of the equation.
7 + -7 + -1b = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -1b = 0 + -7
-1b = 0 + -7

Combine like terms: 0 + -7 = -7
-1b = -7

Divide each side by '-1'.
b = 7

Simplifying
b = 7
Solution
b = {-12, 7}