Chapter R - Elementary Algebra Review - R.4 Polynomials - R.4 Exercise Set - Page 961: 49

$-3x^2y-y^2+8y$

Removing the grouping symbols and then combining like terms, the given expression, $ (-x^2y+2y^2+y)-(3y^2+2x^2y-7y) ,$ simplifies to \begin{array}{l}\require{cancel} -x^2y+2y^2+y-3y^2-2x^2y+7y \\\\= (-x^2y-2x^2y)+(2y^2-3y^2)+(y+7y) \\\\= -3x^2y-y^2+8y .\end{array}