-4w^2-21w-20=0

Solution for -4w^2-21w-20=0 equation:

Simplifying
-4w2 + -21w + -20 = 0

Reorder the terms:
-20 + -21w + -4w2 = 0

Solving
-20 + -21w + -4w2 = 0

Solving for variable 'w'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(20 + 21w + 4w2) = 0

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

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

Simplifying
4 + w = 0

Solving
4 + w = 0

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

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

Combine like terms: 4 + -4 = 0
0 + w = 0 + -4
w = 0 + -4

Combine like terms: 0 + -4 = -4
w = -4

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

Simplifying
5 + 4w = 0

Solving
5 + 4w = 0

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

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

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

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

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

Simplifying
w = -1.25
Solution
w = {-4, -1.25}