[(x)(x)]+9x+20=0

Solution for [(x)(x)]+9x+20=0 equation:

Simplifying
[(x)(x)] + 9x + 20 = 0

Multiply x * x
[x2] + 9x + 20 = 0
x2 + 9x + 20 = 0

Reorder the terms:
20 + 9x + x2 = 0

Solving
20 + 9x + x2 = 0

Solving for variable 'x'.

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

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

Simplifying
5 + x = 0

Solving
5 + x = 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 + x = 0 + -5

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

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

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

Simplifying
4 + x = 0

Solving
4 + x = 0

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

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

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

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

Simplifying
x = -4
Solution
x = {-5, -4}