1.化简:-{-[+(-4)]}=( ) 2.-{-[+(-5)]}与( )互为相反数,-(a-b)与()互为相反数3.-2又七分之四的倒数是()

问题描述:

1.化简:-{-[+(-4)]}=( ) 2.-{-[+(-5)]}与( )互为相反数,-(a-b)与()互为相反数
3.-2又七分之四的倒数是()