## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$1-25t^6$
Using $(a+b)(a-b)=a^2-b^2$ or the product of the sum and difference of like terms, the given expression, $(1-5t^3)(1+5t^3)$, is equivalent to \begin{array}{l}\require{cancel} (1)^2-(5t^3)^2 \\\\= 1-25t^6 .\end{array}