9=x(x-8)

Solution for 9=x(x-8) equation:

Simplifying
9 = x(x + -8)

Reorder the terms:
9 = x(-8 + x)
9 = (-8 * x + x * x)
9 = (-8x + x2)

Solving
9 = -8x + x2

Solving for variable 'x'.

Reorder the terms:
9 + 8x + -1x2 = -8x + 8x + x2 + -1x2

Combine like terms: -8x + 8x = 0
9 + 8x + -1x2 = 0 + x2 + -1x2
9 + 8x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
9 + 8x + -1x2 = 0

Factor a trinomial.
(9 + -1x)(1 + 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 '(1 + x)' equal to zero and attempt to solve:

Simplifying
1 + x = 0

Solving
1 + x = 0

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

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

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

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

Simplifying
x = -1
Solution
x = {9, -1}