= ((х+1)/(х+у)²-1/(х-у)(х+у)) * (х-у)²/(х²-2у-ху) + (у-х)/(х+у)²=
((х+1)(х-у) - (х+у)/(х-у)(х+у)²) * (х-у)²/(х²-2у-ху) + (у-х)/(х+у)²=
((х²+х-ху-у-х-у)/(х-у)(х+у)²) * (х-у)²/(х²-2у-ху) + (у-х)/(х+у)²=
(х²-2у-ху /(х-у)(х+у)²) * (х-у)²/(х²-2у-ху) + (у-х)/(х+у)²=
(1/(х-у)(х+у)²) * (х-у)² + (у-х)/(х+у)²=
х-у /(х+у)² + (у-х)/(х+у)²=
х-у+у-х/(х+у)²= 0/(х+у)² = 0