Answer:
50
Step-by-step explanation:
[tex]i=\sqrt{-1}\to i^2=-1\\\\(3+\sqrt{-16})(6-\sqrt{-64})\\\\\sqrt{-16}=\sqrt{(16)(-1)}=\sqrt{16}\cdot\sqrt{-1}=4i\\\sqrt{-64}=\sqrt{(64)(-1)}=\sqrt{64}\cdot\sqrt{-1}=8i\\\\(3+4i)(6-8i)\\\\\text{use FOIL}\ (a+b)(c+d)=ab+ac+bc+bd\\\\=(3)(6)+(3)(-8i)+(4i)(6)+(4i)(-8i)\\\\=18-24i+24i-32i^2\qquad\text{cancel}\ 24i\\\\=18-32(-1)=18+32=50[/tex]
