16=3x^4+8x^2

Solution for 16=3x^4+8x^2 equation:

Simplifying
16 = 3x4 + 8x2

Reorder the terms:
16 = 8x2 + 3x4

Solving
16 = 8x2 + 3x4

Solving for variable 'x'.

Reorder the terms:
16 + -8x2 + -3x4 = 8x2 + -8x2 + 3x4 + -3x4

Combine like terms: 8x2 + -8x2 = 0
16 + -8x2 + -3x4 = 0 + 3x4 + -3x4
16 + -8x2 + -3x4 = 3x4 + -3x4

Combine like terms: 3x4 + -3x4 = 0
16 + -8x2 + -3x4 = 0

Factor a trinomial.
(4 + -3x2)(4 + x2) = 0

Subproblem 1
Set the factor '(4 + -3x2)' equal to zero and attempt to solve:

Simplifying
4 + -3x2 = 0

Solving
4 + -3x2 = 0

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

Add '-4' to each side of the equation.
4 + -4 + -3x2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -3x2 = 0 + -4
-3x2 = 0 + -4

Combine like terms: 0 + -4 = -4
-3x2 = -4

Divide each side by '-3'.
x2 = 1.333333333

Simplifying
x2 = 1.333333333

Take the square root of each side:
x = {-1.154700538, 1.154700538}
Subproblem 2
Set the factor '(4 + x2)' equal to zero and attempt to solve:

Simplifying
4 + x2 = 0

Solving
4 + x2 = 0

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

Add '-4' to each side of the equation.
4 + -4 + x2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + x2 = 0 + -4
x2 = 0 + -4

Combine like terms: 0 + -4 = -4
x2 = -4

Simplifying
x2 = -4

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.
Solution
x = {-1.154700538, 1.154700538}