f^2+8f-20=0

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

Simplifying
f2 + 8f + -20 = 0

Reorder the terms:
-20 + 8f + f2 = 0

Solving
-20 + 8f + f2 = 0

Solving for variable 'f'.

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

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

Simplifying
-10 + -1f = 0

Solving
-10 + -1f = 0

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

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

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

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

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

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

Simplifying
2 + -1f = 0

Solving
2 + -1f = 0

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

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

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

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

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

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