-4x^2+40=-8x-20

Solution for -4x^2+40=-8x-20 equation:

Simplifying
-4x2 + 40 = -8x + -20

Reorder the terms:
40 + -4x2 = -8x + -20

Reorder the terms:
40 + -4x2 = -20 + -8x

Solving
40 + -4x2 = -20 + -8x

Solving for variable 'x'.

Reorder the terms:
40 + 20 + 8x + -4x2 = -20 + -8x + 20 + 8x

Combine like terms: 40 + 20 = 60
60 + 8x + -4x2 = -20 + -8x + 20 + 8x

Reorder the terms:
60 + 8x + -4x2 = -20 + 20 + -8x + 8x

Combine like terms: -20 + 20 = 0
60 + 8x + -4x2 = 0 + -8x + 8x
60 + 8x + -4x2 = -8x + 8x

Combine like terms: -8x + 8x = 0
60 + 8x + -4x2 = 0

Factor out the Greatest Common Factor (GCF), '4'.
4(15 + 2x + -1x2) = 0

Factor a trinomial.
4((5 + -1x)(3 + x)) = 0

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

Simplifying
5 + -1x = 0

Solving
5 + -1x = 0

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

Add '-5' to each side of the equation.
5 + -5 + -1x = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -1x = 0 + -5
-1x = 0 + -5

Combine like terms: 0 + -5 = -5
-1x = -5

Divide each side by '-1'.
x = 5

Simplifying
x = 5
Subproblem 2
Set the factor '(3 + x)' equal to zero and attempt to solve:

Simplifying
3 + x = 0

Solving
3 + x = 0

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

Add '-3' to each side of the equation.
3 + -3 + x = 0 + -3

Combine like terms: 3 + -3 = 0
0 + x = 0 + -3
x = 0 + -3

Combine like terms: 0 + -3 = -3
x = -3

Simplifying
x = -3
Solution
x = {5, -3}