a=(6radical3+15rad2)ori5 supra rad12+rad50= rationalizam numitorul,adica amplificam fractia cu rad12-rad50 si obtinem (30rad3+75rad2)(rad12-rad50)supra (rad12+rad50)(rad12-rad50)= 30rad3xrad12-30rad3xrad50+75rad2xrad12-75rad2xrad50 supra rad12la puterea a 2 a minus rad50 la a 2a= 30rad36-30rad150+75rad24-75rad100 supra 12-50= se descompun rad 150=5rad6 si rad 24=2rad6 si obtinem 30x6-30x5rad6+75x2rad6-75x10 supra (minus38)= 180-150rad6+150rad6-750 supra -38 (se reduc -150rad6cu+150rad6) si obtinem -570 supra -38= 15 (minus ori minus e plus).
