(1)2x+3y=18?n ①4x?y=5n+1 ②①+②×3,得2x=2n+3,解得x=2n+32,把x=2n+32代入①,得3y=-3n+15,y=-n+5,若x-y=32=2n+32-(-n+5),3=2n+3-10+2n,∴n=52.(2)∵2x+3y=18-n,∴4x+6y=36-2n,∵4x-y=5n+1,∴4x=5n+y+1,∴7y+7n=35,y+n=5,假设y=1,则n=4;假设y=2,则n=3;假设y=3,则n=2;假设y=4,则n=1.那么x=5.5或x=4.5或x=3.5或x=2.5.所以存在.即x=4.5,y=2,n=3或者x=3.5,y=3,n=2.