x*(x+20)=8000

Solution for x*(x+20)=8000 equation:

Simplifying
x(x + 20) = 8000

Reorder the terms:
x(20 + x) = 8000
(20 * x + x * x) = 8000
(20x + x2) = 8000

Solving
20x + x2 = 8000

Solving for variable 'x'.

Reorder the terms:
-8000 + 20x + x2 = 8000 + -8000

Combine like terms: 8000 + -8000 = 0
-8000 + 20x + x2 = 0

Factor a trinomial.
(-100 + -1x)(80 + -1x) = 0

Subproblem 1
Set the factor '(-100 + -1x)' equal to zero and attempt to solve:

Simplifying
-100 + -1x = 0

Solving
-100 + -1x = 0

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

Add '100' to each side of the equation.
-100 + 100 + -1x = 0 + 100

Combine like terms: -100 + 100 = 0
0 + -1x = 0 + 100
-1x = 0 + 100

Combine like terms: 0 + 100 = 100
-1x = 100

Divide each side by '-1'.
x = -100

Simplifying
x = -100
Subproblem 2
Set the factor '(80 + -1x)' equal to zero and attempt to solve:

Simplifying
80 + -1x = 0

Solving
80 + -1x = 0

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

Add '-80' to each side of the equation.
80 + -80 + -1x = 0 + -80

Combine like terms: 80 + -80 = 0
0 + -1x = 0 + -80
-1x = 0 + -80

Combine like terms: 0 + -80 = -80
-1x = -80

Divide each side by '-1'.
x = 80

Simplifying
x = 80
Solution
x = {-100, 80}