Answer
$-30+10i$
Work Step by Step
Using $a(b+c)=ab+ac$, or the Distributive Propert,y and the properties of radicals, the given expression, $
5i(2+6i)
,$ simplifies to
\begin{array}{l}\require{cancel}
5i(2)+5i(6i)
\\\\=
10i+30i^2
\\\\=
10i+30(-1)
\\\\=
10i-30
\\\\=
-30+10i
.\end{array}