[2x/(x-1)-3x/(x+1)]÷x/(x^2-1)=[2x/(x-1)-3x/(x+1)]*(x^2-1)/x=[2x/(x-1)-3x/(x+1)]*(x+1)(x-1)/x=[2x/(x-1)*(x+1)(x-1)/x-3x/(x+1)*(x+1)(x-1)/x(应用分配率)=2(x+1)-3(x-1)=2x+2-3x+3=-x+5