9b^2-8b-20=0

Solution for 9b^2-8b-20=0 equation:

Simplifying
9b2 + -8b + -20 = 0

Reorder the terms:
-20 + -8b + 9b2 = 0

Solving
-20 + -8b + 9b2 = 0

Solving for variable 'b'.

Factor a trinomial.
(-10 + -9b)(2 + -1b) = 0

Subproblem 1
Set the factor '(-10 + -9b)' equal to zero and attempt to solve:

Simplifying
-10 + -9b = 0

Solving
-10 + -9b = 0

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

Add '10' to each side of the equation.
-10 + 10 + -9b = 0 + 10

Combine like terms: -10 + 10 = 0
0 + -9b = 0 + 10
-9b = 0 + 10

Combine like terms: 0 + 10 = 10
-9b = 10

Divide each side by '-9'.
b = -1.111111111

Simplifying
b = -1.111111111
Subproblem 2
Set the factor '(2 + -1b)' equal to zero and attempt to solve:

Simplifying
2 + -1b = 0

Solving
2 + -1b = 0

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

Add '-2' to each side of the equation.
2 + -2 + -1b = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -1b = 0 + -2
-1b = 0 + -2

Combine like terms: 0 + -2 = -2
-1b = -2

Divide each side by '-1'.
b = 2

Simplifying
b = 2
Solution
b = {-1.111111111, 2}