Answer
$4m-3$
Work Step by Step
Given \begin{equation}
\left(4 m^2+25 m-21\right) \div(m+7).
\end{equation} Use long division. $$
\begin{array}{r}
4m-3\phantom{)} \\
m+7{\overline{\smash{\big)}\,4 m^2+25 m-21\phantom{)}}}\\
\underline{-~\phantom{(}(4 m^2+28m)\phantom{-b)}}\\
0-3m-21\phantom{)}\\
\underline{-~\phantom{()}(-3m-21)}\\
0\phantom{)}
\end{array}
$$ The solution is \begin{equation}
\frac{4 m^2+25 m-21}{m+7}=4m-3.
\end{equation}
