Question

已知x,y满足等式2x+x*2+x*2y*2+2=—2xy,则x+y等于多少?

Answer 1

2x+x+xy+2+2xy=0 (x+2x+1)+(xy+2xy+1)=0 (x+1)+(xy+1)=0 x+1=0,xy+1=0 x=-1,y=1,x+y=0 B