化简 (4/x^2-16)+(2/x+4)-(2/x-4)
问题描述：
化简 (4/x^2-16)+(2/x+4)-(2/x-4)
答
12/16-x^2
答
解4/(x²-16)+2/(x+4)-2/(x-4)=4/(x-4)(x+4)+2(x-4)/(x-4)(x+4)-2(x+4)/(x+4)(x-4)=4/(x-4)(x+4)+(2x-8)/(x-4)(x+4)-(2x+8)/(x+4)(x-4)=(4+2x-8-2x-8)/(x-4)(x+4)=-12/(x²-16)