0=x^2+80x-900

Solution for 0=x^2+80x-900 equation:

Simplifying
0 = x2 + 80x + -900

Reorder the terms:
0 = -900 + 80x + x2

Solving
0 = -900 + 80x + x2

Solving for variable 'x'.

Combine like terms: 0 + 900 = 900
900 + -80x + -1x2 = -900 + 80x + x2 + 900 + -80x + -1x2

Reorder the terms:
900 + -80x + -1x2 = -900 + 900 + 80x + -80x + x2 + -1x2

Combine like terms: -900 + 900 = 0
900 + -80x + -1x2 = 0 + 80x + -80x + x2 + -1x2
900 + -80x + -1x2 = 80x + -80x + x2 + -1x2

Combine like terms: 80x + -80x = 0
900 + -80x + -1x2 = 0 + x2 + -1x2
900 + -80x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
900 + -80x + -1x2 = 0

Factor a trinomial.
(10 + -1x)(90 + x) = 0

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

Simplifying
10 + -1x = 0

Solving
10 + -1x = 0

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

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

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

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

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

Simplifying
x = 10
Subproblem 2
Set the factor '(90 + x)' equal to zero and attempt to solve:

Simplifying
90 + x = 0

Solving
90 + x = 0

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

Add '-90' to each side of the equation.
90 + -90 + x = 0 + -90

Combine like terms: 90 + -90 = 0
0 + x = 0 + -90
x = 0 + -90

Combine like terms: 0 + -90 = -90
x = -90

Simplifying
x = -90
Solution
x = {10, -90}