若-(a-5)是负数,则a-5()0 若-[-(x+y)]是负数,则x+y () 0
问题描述:
若-(a-5)是负数,则a-5()0 若-[-(x+y)]是负数,则x+y () 0
答
止住的回想,
若-(a-5)是负数,则a-5>0
若-[-(x+y)]是负数,则X+Y<0