Rewrite as .

Let . Substitute for all occurrences of .

Rewrite as .

Check the middle term by multiplying and compare this result with the middle term in the original expression.

Simplify.

Factor using the perfect square trinomial rule , where and .

Replace all occurrences of with .

Set the equal to .

Add to both sides of the equation.

Take the square root of both sides of the equation to eliminate the exponent on the left side.

The complete solution is the result of both the positive and negative portions of the solution.

First, use the positive value of the to find the first solution.

Next, use the negative value of the to find the second solution.

The complete solution is the result of both the positive and negative portions of the solution.

The result can be shown in multiple forms.

Exact Form:

Decimal Form:

Solve by Factoring x^4-12x^2+36=0