x-2分之2x-6÷（x-2分之5-x-2）
问题描述：
x-2分之2x-6÷（x-2分之5-x-2）
答
原式=[2(x-3)/(x-2)]÷[5/(x-2)-(x+2)]
=[2(x-3)/(x-2)]÷{[5-(x+2)(x-2)]/(x-2)}
=[2(x-3)/(x-2)]÷[(5-x²+4)/(x-2)}
=[2(x-3)/(x-2)]×[(x-2)/(9-x²)]
=2(x-3)/[-(x+3)(x-3)
=-2/(x+3)