Answer
$36a-48b$
Work Step by Step
Using $a(b+c)=ab+ac$ (or the Distributive Property), and then combining like terms, the given expression, $
6[2a+4(a-2b)]
,$ simplifies to
\begin{array}{l}\require{cancel}
6[2a+4a-8b]
\\\\=
6[6a-8b]
\\\\=
36a-48b
.\end{array}