z^2+8z-20=0

Solution for z^2+8z-20=0 equation:

Simplifying
z2 + 8z + -20 = 0

Reorder the terms:
-20 + 8z + z2 = 0

Solving
-20 + 8z + z2 = 0

Solving for variable 'z'.

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

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

Simplifying
-10 + -1z = 0

Solving
-10 + -1z = 0

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

Add '10' to each side of the equation.
-10 + 10 + -1z = 0 + 10

Combine like terms: -10 + 10 = 0
0 + -1z = 0 + 10
-1z = 0 + 10

Combine like terms: 0 + 10 = 10
-1z = 10

Divide each side by '-1'.
z = -10

Simplifying
z = -10
Subproblem 2
Set the factor '(2 + -1z)' equal to zero and attempt to solve:

Simplifying
2 + -1z = 0

Solving
2 + -1z = 0

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

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

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

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

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

Simplifying
z = 2
Solution
z = {-10, 2}