Answer
$-5m^3+2m^2-7m+4$
Work Step by Step
Using the Distributive Property, the given expression, $
(3m^3+2m^2-5m)-(8m^3+2m-4)
,$ is equivalent to
\begin{align*}
&
(3m^3+2m^2-5m)-1(8m^3)-1(2m)-1(-4)
\\&=
3m^3+2m^2-5m-8m^3-2m+4
\\&=
(3m^3-8m^3)+2m^2+(-5m-2m)+4
\\&=
-5m^3+2m^2-7m+4
.\end{align*}
Hence, the expression $
(3m^3+2m^2-5m)-(8m^3+2m-4)
$ is equivalent to $
-5m^3+2m^2-7m+4
$.
