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

$25t^2+60t^3+36t^4$
Using $(a+b)^2=a^2+2ab+b^2$ or the square of a binomial, the given expression, $\left( 5t+6t^2 \right)^2$, is equivalent to \begin{array}{l}\require{cancel} (5t)^2+2(5t)(6t^2)+(6t^2)^2 \\\\= 25t^2+60t^3+36t^4 .\end{array}