我有兩題數學問題不會, 請幫我解開問題, thank you!
1. 若甲=6666....6, 共一百位數, 求甲除9的餘數?
2. 9999999999*5555555555之積的各個數字總和是多少?
若甲=6666....6, 共一百位數, 求甲除9的餘數?
2013-07-29 10:32 pm
回答 (6)
2013-07-30 3:53 am
✔ 最佳答案
1. 若甲=6666....6, 共一百位數，求甲除9的餘數?Sol
6*100/9=66……..6
餘數=6
2. 9999999999*5555555555之積的各個數字總和是多少?
Sol
9999999999*5555555555
=(10000000000－1)*5555555555
=55555555550000000000－5555555555
=55555555544444444445
5*(9+1)+4*10
=90
or
9*5=45
4+5=9
a1=9
99*55=5445
5*2+4*2=18
a2=18
a3=999*555=554445
5*3+4*3=27
a3=27
9999*5555=55544445
5*4+4*4=36
a4=36
成等差a1=9，d=9
a10=a1+9d=9+9*8=90
2014-07-28 2:22 pm
2014-06-26 10:01 am
2013-07-30 1:38 am
9999999999*5555555555
=(10000000000-1)*5555555555
=55555555550000000000 - 5555555555
=55555555544444444445
總和=5*10+4*10 = 90
=(10000000000-1)*5555555555
=55555555550000000000 - 5555555555
=55555555544444444445
總和=5*10+4*10 = 90
2013-07-29 11:22 pm
(1)
Sol
666(mod9)=0
So
(666*10^97+666*10^94+666*10^1+6) (mod9)=6
(2):
9*1111111111*5*1111111111
=45*(1111111111)^2
Sol
5+4+(5+4)*(10-1) = 90.
Sol
666(mod9)=0
So
(666*10^97+666*10^94+666*10^1+6) (mod9)=6
(2):
9*1111111111*5*1111111111
=45*(1111111111)^2
Sol
5+4+(5+4)*(10-1) = 90.
2013-07-29 11:11 pm
9x5=54??
這個......= =
這個......= =
收錄日期: 2021-04-30 17:56:26
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130729000015KK02644