20b^2-9b-20=0

Solution for 20b^2-9b-20=0 equation:

Simplifying
20b2 + -9b + -20 = 0

Reorder the terms:
-20 + -9b + 20b2 = 0

Solving
-20 + -9b + 20b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-4 + -5b)(5 + -4b) = 0

Subproblem 1
Set the factor '(-4 + -5b)' equal to zero and attempt to solve:

Simplifying
-4 + -5b = 0

Solving
-4 + -5b = 0

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

Add '4' to each side of the equation.
-4 + 4 + -5b = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -5b = 0 + 4
-5b = 0 + 4

Combine like terms: 0 + 4 = 4
-5b = 4

Divide each side by '-5'.
b = -0.8

Simplifying
b = -0.8
Subproblem 2
Set the factor '(5 + -4b)' equal to zero and attempt to solve:

Simplifying
5 + -4b = 0

Solving
5 + -4b = 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 + -4b = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -4b = 0 + -5
-4b = 0 + -5

Combine like terms: 0 + -5 = -5
-4b = -5

Divide each side by '-4'.
b = 1.25

Simplifying
b = 1.25
Solution
b = {-0.8, 1.25}