Question(6) An integrating factor that makes the differential equation $$x y^{2} d x+(x y-y) d y=0, \quad x>1$$ exact is (a) $x \mathrm{e}^{2 x}$ (b) $(x-1) \mathrm{e}^{2 x}$ (c) $e^{2 x}$ (d) $(x+1)^{-3} e^{2 x}$ (e) $(x-1) e^{-2 x}$