题目内容
用等号“=”或不等号“≠”填空∶
(1)5+3________5+4;
(2)8+(-4)________8-(+4).
用等号或不等号填空:
(1)比较2x与+1的大小:
①当x=2时,2x________;
②当x=1时,2x________;
③当x=-1时,2x________.
(2)推测:当x取任意实数时,2x________.