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+3)(x-3)/(x-2)]=-2(x-3)(x-2)/[(x-2)(x+3)(x-3)]=-2/(x+3)佩服，再问一下，除号怎么打？我用的是搜狗。。。直接打"chu“第五个就是÷