20z^2-9z-20=

Solution for 20z^2-9z-20= equation:

Simplifying
20z2 + -9z + -20 = 0

Reorder the terms:
-20 + -9z + 20z2 = 0

Solving
-20 + -9z + 20z2 = 0

Solving for variable 'z'.

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

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

Simplifying
-4 + -5z = 0

Solving
-4 + -5z = 0

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

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

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

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

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

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

Simplifying
5 + -4z = 0

Solving
5 + -4z = 0

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

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

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

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

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

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