20b^2-13b=15

Solution for 20b^2-13b=15 equation:

Simplifying
20b2 + -13b = 15

Reorder the terms:
-13b + 20b2 = 15

Solving
-13b + 20b2 = 15

Solving for variable 'b'.

Reorder the terms:
-15 + -13b + 20b2 = 15 + -15

Combine like terms: 15 + -15 = 0
-15 + -13b + 20b2 = 0

Factor a trinomial.
(-3 + -5b)(5 + -4b) = 0

Subproblem 1
Set the factor '(-3 + -5b)' equal to zero and attempt to solve:

Simplifying
-3 + -5b = 0

Solving
-3 + -5b = 0

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

Add '3' to each side of the equation.
-3 + 3 + -5b = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -5b = 0 + 3
-5b = 0 + 3

Combine like terms: 0 + 3 = 3
-5b = 3

Divide each side by '-5'.
b = -0.6

Simplifying
b = -0.6
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 = {-0.6, 1.25}