Chapter 4 - Polynomials - 4.6 Special Products - 4.6 Exercise Set - Page 277: 70

$9p^4-6p^3+p^2$

Using $(a+b)^2=a^2+2ab+b^2$ or the square of a binomial, the given expression, $ \left( 3p^2-p \right)^2 $, is equivalent to \begin{array}{l}\require{cancel} (3p^2)^2+2(3p^2)(-p)+(-p)^2 \\\\= 9p^4-6p^3+p^2 .\end{array}