15x^4-7x^2-2=0

Solution for 15x^4-7x^2-2=0 equation:

Simplifying
15x4 + -7x2 + -2 = 0

Reorder the terms:
-2 + -7x2 + 15x4 = 0

Solving
-2 + -7x2 + 15x4 = 0

Solving for variable 'x'.

Factor a trinomial.
(-1 + -5x2)(2 + -3x2) = 0

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

Simplifying
-1 + -5x2 = 0

Solving
-1 + -5x2 = 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 + -5x2 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -5x2 = 0 + 1
-5x2 = 0 + 1

Combine like terms: 0 + 1 = 1
-5x2 = 1

Divide each side by '-5'.
x2 = -0.2

Simplifying
x2 = -0.2

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 '(2 + -3x2)' equal to zero and attempt to solve:

Simplifying
2 + -3x2 = 0

Solving
2 + -3x2 = 0

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

Add '-2' to each side of the equation.
2 + -2 + -3x2 = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -3x2 = 0 + -2
-3x2 = 0 + -2

Combine like terms: 0 + -2 = -2
-3x2 = -2

Divide each side by '-3'.
x2 = 0.6666666667

Simplifying
x2 = 0.6666666667

Take the square root of each side:
x = {-0.816496581, 0.816496581}
Solution
x = {-0.816496581, 0.816496581}