4x^4+8x^2-5=0

Solution for 4x^4+8x^2-5=0 equation:

Simplifying
4x4 + 8x2 + -5 = 0

Reorder the terms:
-5 + 8x2 + 4x4 = 0

Solving
-5 + 8x2 + 4x4 = 0

Solving for variable 'x'.

Factor a trinomial.
(-5 + -2x2)(1 + -2x2) = 0

Subproblem 1
Set the factor '(-5 + -2x2)' equal to zero and attempt to solve:

Simplifying
-5 + -2x2 = 0

Solving
-5 + -2x2 = 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 + -2x2 = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -2x2 = 0 + 5
-2x2 = 0 + 5

Combine like terms: 0 + 5 = 5
-2x2 = 5

Divide each side by '-2'.
x2 = -2.5

Simplifying
x2 = -2.5

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 + -2x2)' equal to zero and attempt to solve:

Simplifying
1 + -2x2 = 0

Solving
1 + -2x2 = 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 + -2x2 = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -2x2 = 0 + -1
-2x2 = 0 + -1

Combine like terms: 0 + -1 = -1
-2x2 = -1

Divide each side by '-2'.
x2 = 0.5

Simplifying
x2 = 0.5

Take the square root of each side:
x = {-0.707106781, 0.707106781}
Solution
x = {-0.707106781, 0.707106781}