問1: 2,5,8,9,12,15,17,22,29,
Prime numbers:_____________
Composite number:____________________
問2:write down all the prime numbers between 1and 50.
2,__,__,7,11,__,__,19,__,__,31,__,__,__,47
問3:write down all the prime numbers from 51 to 100.
_________________________.
問4:show that 361 is not a prime number .
__________________________.
問4:find the units digit of the expression (5×2)+(5×4)+（5×6）+（5×8）+...+（5×998）.briefly explain your answer.
以上問題非常緊急!!!!希望快d有人幫到我><!!!thx
有數學問題請教, P6.-S1
2010-07-21 2:27 am
回答 (3)
2010-07-21 3:17 am
✔ 最佳答案
答1: 質數:2,5,9,17,29合成數:8,12,15,22
答2: 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47
答3:
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,57,59,61,67,71,73,79,83,87,89,91,97
答4:361唔係質數
find the units digit of the expression (5×2)+(5×4)+（5×6）+（5×8）+...+（5×998）.briefly explain your answer.
呢條唔識
2010-07-22 12:42 am
1. prime no. 2,5,17,18
Composite no.8,9,12,15,22
2. 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47
3.51,53,57,59,61,67,71,73,79,83,87,89,97
4. 19*19 = 361
so it is not a prime number.
5. All of them are zero, because when 5 multiply with an even number (2,4,6,8), the product must can be divided into 10
easy job!!!
Composite no.8,9,12,15,22
2. 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47
3.51,53,57,59,61,67,71,73,79,83,87,89,97
4. 19*19 = 361
so it is not a prime number.
5. All of them are zero, because when 5 multiply with an even number (2,4,6,8), the product must can be divided into 10
easy job!!!
2010-07-21 2:37 am
1. prime no. 2,5,17,18
Composite no.8,9,12,15,22
2. 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47
3.51,53,57,59,61,67,71,73,79,83,87,89,97
4. 19*19 = 361
so it is not a prime number.
5. All of them are zero, because when 5 multiply with an even number (2,4,6,8), the product must can be divided into 10
Composite no.8,9,12,15,22
2. 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47
3.51,53,57,59,61,67,71,73,79,83,87,89,97
4. 19*19 = 361
so it is not a prime number.
5. All of them are zero, because when 5 multiply with an even number (2,4,6,8), the product must can be divided into 10
收錄日期: 2021-04-13 17:22:55
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