I think it wants me to show that there's no bijection between the two sets.
I first tried to show that there's simply no bijection, then I realised that it doesn't work.
If I'm to show there's no bijective morphism that carries multiplication in nonzero real numbers to addition in real numbers, how am I supposed to do it? I'm thinking about doing something with 0, since it's the element of the first set but not the second set.
Thanks!