## Intermediate Algebra (6th Edition)

$x^{2a}-y^{4b}$
Using $(a+b)(a-b)=a^2-b^2$ or the product of the sum and difference of like terms and using the laws of exponents, the given expression, $(x^a+y^{2b})(x^{a}-y^{2b})$, is equivalent to \begin{array}{l}\require{cancel} (x^{a})^2-(y^{2b})^2 \\\\= x^{2a}-y^{4b} .\end{array}