-8,0.275, ,0,-1.04,-(-3),- ,|-2|.
正数集合{ };
负整数集合{ };
分数集合{ };
负数集合{ }.
+5,-3,+11,-8,+12,-6,-11.
-1,2,-3,4,-5,( ),( ),…;
1,4,9,16,25,( ),( ),…;
0,3,8,15,24,( ),( ),….