(+1)+(-2)+(+3)+(-4)+...+(+99)+(-100) 算的方法是?(+1)+(-2)+(+3)+(-4)+...+(+99)+(-100) 怎算呢?

来源：学生作业学帮网编辑：学帮网时间：2024/06/25 08:59:31

(+1)+(-2)+(+3)+(-4)+...+(+99)+(-100) 算的方法是?
(+1)+(-2)+(+3)+(-4)+...+(+99)+(-100) 怎算呢?

(+1)+(-2)+(+3)+(-4)+...+(+99)+(-100)
= (1 - 2) + (3 - 4) + ...+ (99 - 100)
= (-1) + (-1) + ...+ (-1) (一共50个 -1)
= (-1) × 50
= -50

1 2 3 4 1 2 3 4 1 2 3 4 1,2,3,4, 1 2 3 4 1 2 3 4 1,2,3,4, 1,2,3,4, 1,2,3,4, 1,2,3,4, 1 2 3 4 1,2,3,4, 1,2,3,4, 1,2,3,4, 1、2、3、4 1+2+3×4 1,2,3,4 1+2+3+4+.