若-(a-5)是负数,则a= 5;若-[-(x-y)]是负数,则x+y= 0.(填‘’,或等于 ) 急

问题描述:

若-(a-5)是负数,则a= 5;若-[-(x-y)]是负数,则x+y= 0.(填‘’,或等于 ) 急

-(a-5)0
则a>5
-[-(x-y)]