(1)x(x+1)/(x+1)(x-1)=x/x-1 (2)(x-3)^2 2.x^2-8x+16/x^2-16=(x-4)^2/(x+4)(x-4)=x-4/x+4=11/19
3.是2a/a^2-4和1/a-2么.那就是后者分母乘以a+2