Resistivity AS question HELP

I just have no idea where to start with this question to get a sensible answer...
I've tried rearranging p=RA/L to find L but it doesn't really work :/
I'm probably over complicating it but any help would be much appreciated

Well, it tells you that your length is 'x'. Therefore, your area must be 'x' to the power of 2 ( as x is multiplied by itself).

So, if you substitute it, the you get p=R(x)2/x

Cancel your x's to get p=Rx

Rearrange and you get x=p/R, which is 5x10-2/5 = 0.01m
Hope this helps

P.s, if you substitute it into the equation you'll see that the answer for resistivity is 0.05, which is 5x10-2

Thank you !! Yes I understand - I had the right idea but I think I was getting myself all confused because I rearranged it first and subbed in R straight away