Answer
$7+2i$
Work Step by Step
Factor the radicand so that one factor $-1$ to obtain:
$=7+\sqrt{4(-1)}
\\=7+\sqrt{2^2(-1)}$
RECALL:
(1) $\sqrt{ab} = \sqrt{a} \cdot \sqrt{b}$
(2) $\sqrt{-1} = i$
Use rule (1) above to obtain:
$=7+ \cdot \sqrt{2^2} \cdot \sqrt{-1}
\\=7+ 2 \cdot \sqrt{-1}$
Use rule (2) above to obtain:
$=7+2 \cdot i
\\=7+2i$
