5/(x-3)-(2x-5)/(x^2-3x)=5x/x(x-3)-(2x-5)/x(x-3)=(5x-2x+5)/x(x-3)=(3x+5)/x(x-3) x^2/(x^2-y^2)-x/(x+y )=x²/(x-y)(x+y)-x(x-y)/(x+y)(x-y)=(x²-x²+xy)/(x+y)(x-y)=xy/(x+y)(x-y)