(2х+3)/(х+1)+(2+3х)/(х+1)=(2х+3+2+3х)/(х+1)=(5х+5)/(х+1)=5(х+1)/(х+1)=5
3х/(х-2)+(2х+2)/(2-х)=(3х(2-х)+(2х+2)(х-2))/((х-2)(2-х))=(6х-3х^2+2х^2-4х+2х-4)/(2х-х^2-4+2х)=(-х^2-4х-4)/(-х^2-4+4х)=(х^2+4х+4)/(х^2-4х+4)=(х+2)^2/(х-2)^2
(7х-2)/(х-1)-5/(х-1)=(7х-2-5)/(х-1)=(7х-7)/(х-1)=7(х-1)/(х-1)=7
(3х-5)/(х-4у) - (1-3у)/(4у-х)=((3х-5)(4у-х)-(1-3у)(х-4у))/((х-4у)(4у-х))=(12ху-20у-3х^2+5х-х+4у+3ху-12у^2)/(4ху-х^2-16у^2+4х)=(-3х^2-12у^2+15ху+4х-16у)/(-х^2-16у^2+4ху+4у)