Multiply by .

Combine.

Apply the distributive property.

Cancel the common factor of .

Factor out of .

Cancel the common factor.

Rewrite the expression.

Cancel the common factor of .

Move the leading negative in into the numerator.

Cancel the common factor.

Rewrite the expression.

Factor out of .

Factor out of .

Factor out of .

Factor out of .

Multiply by .

Rewrite as .

Rewrite as .

Since both terms are perfect squares, factor using the difference of squares formula, where and .

Simplify.

Multiply by .

Multiply by .

Cancel the common factor.

Rewrite the expression.

Simplify (1+4/x)/(1-16/(x^2))