12/x^2-9+2/3-x 分式计算
问题描述：
12/x^2-9+2/3-x 分式计算
答
12/x^2-9+2/3-x
=12/x^2-9 -2/x-3
=(12-2(x+3))/(x^2-9)
=(12-2x-6)/(x^2-9)
=(6-2x)/(x^2-9)
=-2(x-3)/(x-3)(x+3)
=-2/(x+3)
答
原式=12/(x+3)(x-3)-2(x+3)/(x+3)(x-3)
=(12-2x-6)/(x+3)(x-3)
=-2(x-3)/(x+3)(x-3)
=-2/(x+3)