问题 解答题

(1)100-98+96-94+92-90+…+8-6+4-2

(2)1001×1001-1001.

答案

(1)100-98+96-94+92-90+…+8-6+4-2,

=(100-98)+(96-94)+(92-90)+…+(8-6)+(4-2),

=2×25,

=50;

(2)1001×1001-1001

=(1001-1)×1001,

=1000×1001,

=1001000.

单项选择题
单项选择题 A1/A2型题