Please help asap, ty!!

Note.....   ⁿ√a^m   =  a^m/n  .... so.....

⁵√w³  is equivalent to    w^3/5  =  ( w^1/5 ) ³  ⇒​   "D"

Second one

Let the width be, W

So the length is 10 more than this  = W + 10

And 

Area  = W * L  =  W (W + 10)  = f(W)