880=xy(x+y)=xy(71-xy)(xy)2-71xy+880=0(xy-16)(xy-55)=0880=xy(x+y)=(x+y)(71-x-y)同理有x+y=16或x+y=55又∵xy+x+y=71∴x=11,y=5或x=5,y=11∴?=121+25=146
