Answer
$-x+12$
Work Step by Step
Removing the grouping symbols and then combining like terms, the given expression, $
(3x+5)-(4x-7)
,$ simplifies to
\begin{array}{l}\require{cancel}
3x+5-4x+7
\\\\=
(3x-4x)+(5+7)
\\\\=
-x+12
.\end{array}