How do you multiply and simplify radical 2(radical 8+ radical 5)?

Answer 1

do you mean "square root" for the "radical"? if so,
2[sqrt(8) + sqrt(5)]
note that we cannot combine the radical terms since their radicands (term inside the radical sign) are not equal. but we can rewrite this as
2[2*sqrt(2) + sqrt(5)]
4*sqrt(2) + 2*sqrt(5)

hope this helps~ :)