Answer
$4t^2+5t-12$
Work Step by Step
Removing the grouping symbols and then combining like terms, the given expression, $
(4t^2+6t-7)-(t+5)
,$ simplifies to
\begin{array}{l}\require{cancel}
4t^2+6t-7-t-5
\\\\=
4t^2+(6t-t)+(-7-5)
\\\\=
4t^2+5t-12
.\end{array}