81x^4-81=

Solution for 81x^4-81= equation:

Simplifying
81x4 + -81 = 0

Reorder the terms:
-81 + 81x4 = 0

Solving
-81 + 81x4 = 0

Solving for variable 'x'.

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

Add '81' to each side of the equation.
-81 + 81 + 81x4 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + 81x4 = 0 + 81
81x4 = 0 + 81

Combine like terms: 0 + 81 = 81
81x4 = 81

Divide each side by '81'.
x4 = 1

Simplifying
x4 = 1

Reorder the terms:
-1 + x4 = 1 + -1

Combine like terms: 1 + -1 = 0
-1 + x4 = 0

Factor a difference between two squares.
(1 + x2)(-1 + x2) = 0

Factor a difference between two squares.
(1 + x2)((1 + x)(-1 + x)) = 0

Subproblem 1
Set the factor '(1 + x2)' equal to zero and attempt to solve:

Simplifying
1 + x2 = 0

Solving
1 + x2 = 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 + x2 = 0 + -1

Combine like terms: 1 + -1 = 0
0 + x2 = 0 + -1
x2 = 0 + -1

Combine like terms: 0 + -1 = -1
x2 = -1

Simplifying
x2 = -1

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.
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
Subproblem 3
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 = {-1, 1}