题目内容
(1)当x<5时,的值是 ( )
A.x-5 B.5-x C.5+x D.-5-x
(2)当a>0时,化简等于 ( )
A.0 B.2a C.-2a D.a
(3)若x<-2,化简|x+2|-等于 ( )
A.2x B.2x-4 C.-4 D.4
(1); (2);
(3); (4)(m>1).