1)(5/х-у-5х/у²-х²)х²=(5/х-у+5х/х²-у²)х²=(10х+5у/(х-у)(х+у))х²=5х²(2х+у)/(х-у)(х+у)
2)2ху+у²/10х+5у=2у(х+у)/5(х+у)=2у/5
3) 5х²(2х+у)/(х-у)(х+у)+2у/5=5(5х²(2х+у)+2у(х²-у²)/5(х-у)(х+у)=25х²(2х+у)+2ух²-2у³/5(х-у)(х+у)=5х²(2х+у)2у(х²-у²)/х²-у²=5х²(2х+у)+2у
4)5*(3,5)²(2*3,5-0,5+2(-0,5)=61,25(7-0,5-1)=336,875