Answer
$9-12i$
Work Step by Step
Using the FOIL Method which is given by $(a+b)(c+d)=ac+ad+bc+bd,$ the given expression is equivalent to
\begin{array}{l}\require{cancel}
(6-3i)(2-i)
\\\\=
6(2)+6(-i)-3i(2)-3i(-i)
\\\\=
12-6i-6i+3i^2
.\end{array}
Since $i^2=-1,$ the expression above is equivalent to
\begin{array}{l}\require{cancel}
12-6i-6i+3i^2
\\\\=
12-6i-6i+3(-1)
\\\\=
12-6i-6i-3
\\\\=
(12-3)+(-6i-6i)
\\\\=
9-12i
.\end{array}