What does $(2 - i) (4 + 2 i) + 3 i$ $(2-i)(4+2i)+3i$ equal in a + bi form?

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Answer 1 · 2015-10-21T00:44:21

I found: $10 + 3 i$ $10+3i$

First multiply:
$8cancel(+4i)cancel(-4i)-2i^2+3i=$
remember that $i^2=-1$
so:
$=8+2+3i=$
$=10+3i$

What does (2-i)(4+2i)+3i(2−i)(4+2i)+3i(2-i)(4+2i)+3i equal in a + bi form?