解:∵(x-y)^2≥0,|3x-2y-2|≥0;且(x-y)^2+|3x-2y-2|≤0∴(x-y)^2=0,3x-2y-2=0,即y=2,x=2∴x+y=2+2=4
∵(X-Y)²+|3X-2Y-2|≤0∴X-Y=0①3X-2Y-2=0②∴x=2,y=2∴x+y=4