[tex]4\sqrt{32}\times\sqrt{2}\rightarrow4\sqrt{32\times2}[/tex] because two square rooted numbers multiplied together equals the square root of the radicands (the number under a square root symbol is the "radicand"
so now you have: [tex]4\sqrt{64}=4\times(\pm8)[/tex]
Depending on the choices, you can have either [tex]4\times8=32[/tex] or [tex]4\times(-8)=-32[/tex]
