20b^2-48b-128=

Solution for 20b^2-48b-128= equation:

Simplifying
20b2 + -48b + -128 = 0

Reorder the terms:
-128 + -48b + 20b2 = 0

Solving
-128 + -48b + 20b2 = 0

Solving for variable 'b'.

Factor out the Greatest Common Factor (GCF), '4'.
4(-32 + -12b + 5b2) = 0

Factor a trinomial.
4((-8 + -5b)(4 + -1b)) = 0

Ignore the factor 4.
Subproblem 1
Set the factor '(-8 + -5b)' equal to zero and attempt to solve:

Simplifying
-8 + -5b = 0

Solving
-8 + -5b = 0

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

Add '8' to each side of the equation.
-8 + 8 + -5b = 0 + 8

Combine like terms: -8 + 8 = 0
0 + -5b = 0 + 8
-5b = 0 + 8

Combine like terms: 0 + 8 = 8
-5b = 8

Divide each side by '-5'.
b = -1.6

Simplifying
b = -1.6
Subproblem 2
Set the factor '(4 + -1b)' equal to zero and attempt to solve:

Simplifying
4 + -1b = 0

Solving
4 + -1b = 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 + -1b = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1b = 0 + -4
-1b = 0 + -4

Combine like terms: 0 + -4 = -4
-1b = -4

Divide each side by '-1'.
b = 4

Simplifying
b = 4
Solution
b = {-1.6, 4}