Question

100+200+..........+800+900+1000=?

Answer 1

5500

k nha ^-^

Answer 2

Dãy số có ssh là :

            ( 1000-100):100+1=10 ( số )

Tổng  là : ( 1000+100)x10:2=5500

Answer 3

100+200+..........+800+900+1000

=5500

chn mình nha  các bạn 

Answer 4

= (100+900)+(200+800)+(300+700)+(400+600)+1000+500

= 1000+1000+1000+1000+1000+500

= 1000x5+500

= 5000+500

= 5500

Answer 5

[(1000-100):100+1]x(1000+100):2=5500

Answer 6

100+200+...+800+900+1000

=(900+100)+(800+200)+(700+300)+(600+400)+1000+500

=1000+1000+1000+1000+1000+500

=5000+500

5500

Answer 7

dễ ẹt, bạn hk lớp mấy vậy Hắt xù!

Answer 8

=100+200+300+400+500=600+700+800+900+1000

=[100+900]+[200+800]+[300+700]+[400+600]+500

=1000+1000+1000+1000+500

=4000+500

=4500