x、y、z≠-1、0解:由①:yz+y=x+1…④由②:zx+z=y+1…⑤由③:xy+x=z+1…⑥④+⑤+⑥:xy+yz+xz=3…⑦①x②x③:xyz=1∴z=1/xy分别代入④、⑦:代入④:1/x+y=x+1∴1+xy=x²+x∴y=(x²+x-1)/x…⑧代入⑦:xy+