х-х/x+1
x/x+y + y/x-y
m+2/4m - 1/m+4
Х-х/x+1=х x/x+y + y/x-y=х(х-у)+у(х+у)/(х+у)(х-у)=x^2-ху+у^2+ху=х^2+у^2/(х+у)(х-у) m+2/4m - 1/m+4=m+2/4m-4/4m+4=m-1/2m+4
1) х - х/х + 1 = х - 1 + 1 = х 2) х/х + у + у/х - у = 1 + у/х = (х + у)/х 3) m + 2/4m - 1/ m + 4 = m + 1/m - 1/m + 4 = m + 4