x^2-8x+16=81

Solution for x^2-8x+16=81 equation:

Simplifying
x2 + -8x + 16 = 81

Reorder the terms:
16 + -8x + x2 = 81

Solving
16 + -8x + x2 = 81

Solving for variable 'x'.

Reorder the terms:
16 + -81 + -8x + x2 = 81 + -81

Combine like terms: 16 + -81 = -65
-65 + -8x + x2 = 81 + -81

Combine like terms: 81 + -81 = 0
-65 + -8x + x2 = 0

Factor a trinomial.
(-5 + -1x)(13 + -1x) = 0

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

Simplifying
-5 + -1x = 0

Solving
-5 + -1x = 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 + -1x = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1x = 0 + 5
-1x = 0 + 5

Combine like terms: 0 + 5 = 5
-1x = 5

Divide each side by '-1'.
x = -5

Simplifying
x = -5
Subproblem 2
Set the factor '(13 + -1x)' equal to zero and attempt to solve:

Simplifying
13 + -1x = 0

Solving
13 + -1x = 0

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

Add '-13' to each side of the equation.
13 + -13 + -1x = 0 + -13

Combine like terms: 13 + -13 = 0
0 + -1x = 0 + -13
-1x = 0 + -13

Combine like terms: 0 + -13 = -13
-1x = -13

Divide each side by '-1'.
x = 13

Simplifying
x = 13
Solution
x = {-5, 13}