1. ## vector question

Hi, I'm stuck on the following question:

find vectors parallet to the xy plane that are perpendicular to the vector (-2,3,5)

My attempt:
I realise that the z co-ord in these 2 vectors would be the same so I let m and n be the 2 vectors, where m=(a,b,c) and n=(d,e,c)
I then tried to find the cross product of m and n as that would equate to (-2,3,5) but came out with 5 unknowns and 3 equations...