1. The problem statement, all variables and given/known data Number 1 2. Relevant equations I know I should use a Venn diagram. 3. The attempt at a solution The statement says that x intersects y so therefore the statement equals x minus y. This Is my attempt at the solution, if you subtract y from the venn diagram you get this partially eaten cookie shape... So would that be enough to prove a it? My explanation would be that since what is left of x is clearly not a full set and some where y intersects x.