упростить x^2/x^2-1-x/x+1

х^2/(х^2-1) - х/(х+1) = х^2/[(х+1)(х-1)] - х/(х+1) = = х^2/[(х+1)(х-1)] - х(х-1)/[(х+1)(х-1)] = = (х^2 - х*2 +1)/[(х+1)(х-1)] == 1/(х^2-1)