Answer
$-2x^3-10x^2+6x$
Work Step by Step
Using $a(b+c)=ab+ac$ or the Distributive Property, the given expression, $
(x^2+5x-3)(-2x)
,$ is equivalent to
\begin{array}{l}\require{cancel}
x^2(-2x)+5x(-2x)-3(-2x)
\\\\=
-2x^3-10x^2+6x
.\end{array}