5b^2-8b-85=0

Solution for 5b^2-8b-85=0 equation:

Simplifying
5b2 + -8b + -85 = 0

Reorder the terms:
-85 + -8b + 5b2 = 0

Solving
-85 + -8b + 5b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-17 + -5b)(5 + -1b) = 0

Subproblem 1
Set the factor '(-17 + -5b)' equal to zero and attempt to solve:

Simplifying
-17 + -5b = 0

Solving
-17 + -5b = 0

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

Add '17' to each side of the equation.
-17 + 17 + -5b = 0 + 17

Combine like terms: -17 + 17 = 0
0 + -5b = 0 + 17
-5b = 0 + 17

Combine like terms: 0 + 17 = 17
-5b = 17

Divide each side by '-5'.
b = -3.4

Simplifying
b = -3.4
Subproblem 2
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
Solution
b = {-3.4, 5}