0=X^2+81X-810

Solution for 0=X^2+81X-810 equation:

Simplifying
0 = X2 + 81X + -810

Reorder the terms:
0 = -810 + 81X + X2

Solving
0 = -810 + 81X + X2

Solving for variable 'X'.

Combine like terms: 0 + 810 = 810
810 + -81X + -1X2 = -810 + 81X + X2 + 810 + -81X + -1X2

Reorder the terms:
810 + -81X + -1X2 = -810 + 810 + 81X + -81X + X2 + -1X2

Combine like terms: -810 + 810 = 0
810 + -81X + -1X2 = 0 + 81X + -81X + X2 + -1X2
810 + -81X + -1X2 = 81X + -81X + X2 + -1X2

Combine like terms: 81X + -81X = 0
810 + -81X + -1X2 = 0 + X2 + -1X2
810 + -81X + -1X2 = X2 + -1X2

Combine like terms: X2 + -1X2 = 0
810 + -81X + -1X2 = 0

Factor a trinomial.
(9 + -1X)(90 + X) = 0

Subproblem 1
Set the factor '(9 + -1X)' equal to zero and attempt to solve:

Simplifying
9 + -1X = 0

Solving
9 + -1X = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1X = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1X = 0 + -9
-1X = 0 + -9

Combine like terms: 0 + -9 = -9
-1X = -9

Divide each side by '-1'.
X = 9

Simplifying
X = 9
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 = {9, -90}