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

$25-20t^3+4t^6$
Using $(a+b)^2=a^2+2ab+b^2$ or the square of a binomial, the given expression, $\left( 5-2t^3 \right)^2$, is equivalent to \begin{array}{l}\require{cancel} (5)^2+2(5)(-2t^3)+(-2t^3)^2 \\\\= 25-20t^3+4t^6 .\end{array}