Answer
$2a^3-9a^2+10a-3$
Work Step by Step
Using the Distributive Property, the given expression, $
(2a-1)(a^2-4a+3)
,$ is equivalent to
\begin{array}{l}\require{cancel}
2a(a^2)+2a(-4a)+2a(3)-1(a^2)-1(-4a)-1(3)
\\\\=
2a^3-8a^2+6a-a^2+4a-3
\\\\=
2a^3+(-8a^2-a^2)+(6a+4a)-3
\\\\=
2a^3-9a^2+10a-3
.\end{array}