Factor out of .

Factor out of .

Factor out of .

Factor out of .

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

Simplify.

Add and .

Subtract from .

Add and .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Apply the distributive property.

Multiply by .

Simplify (3(a+h)^2-3a^2)/h