计算【1/（x-2）】-【1/（x+2）】+【（x2-4x）/（x2-4）】
问题描述：
计算【1/（x-2）】-【1/（x+2）】+【（x2-4x）/（x2-4）】
答
=[x+2-(x-2)]/[(x+2)(x-2)]+[x2-4x)]/[(x+2)(x-2)]
=(x2-4x+4)/[(x-2)(x+2)]
=[(x-2)(x-2)]/[(x-2)(x+2)]
=(x-2)/(x+2)
答
=π =0 =213123。31411234123421341234
答
原式=[(x+2)-(x-2)]/(x+2)(x-2)+(x2-4x)/(x+2)(x-2)
=4/(x+2)(x-2)+(x2-4x)/(x+2)(x-2)
=(x2-4x+4)/(x+2)(x-2)
=(x-2)2/(x+2)(x-2)
==(x-2)/(x+2)