Answer
$-5r^2t-6rt+6rt^2$
Work Step by Step
Removing the grouping symbols and then combining like terms, the given expression, $
(2r^2t-5rt+rt^2)-(7r^2t+rt-5rt^2)
,$ simplifies to
\begin{array}{l}\require{cancel}
2r^2t-5rt+rt^2-7r^2t-rt+5rt^2
\\\\=
(2r^2t-7r^2t)+(-5rt-rt)+(rt^2+5rt^2)
\\\\=
-5r^2t-6rt+6rt^2
.\end{array}
