各位中一or二的人請進,急..暑期作業10分英皇學生

🎓 學業台小學及中學教育

Ho Chun

2007-08-17 10:47 pm

有一條math嘅數希望大家教我
Start > Input a 3-digit number. >Multiply the number by 77 >Multiply the product by 13 >Result
下列有兩條問題:(a)what do you discover?(b)can you explain the dicovery(急)

更新1:

快D!!!!!!!!我要(b)既先

更新2:

正啊,聽日呢..選你啦

回答 (2)

Kenneth

2007-08-17 11:03 pm

✔ 最佳答案

a) assume the 3 digit number is abc
the 3 digit number become 6 digit number
ie.) abc -> abcabc

b) because multiply the product by 77 and then multiply again by 13 is equivalent to direct multiply the product by 1001
(abc *77)*13 = abc * 1001 = abcabc

👍 0 👎 0

shadow

2007-08-17 11:11 pm

Let 3-digit number be xxx

[(xxx) x77]x13
= (xxx) x 1001
= (xxx) x (1000+1)
= xxx000 + xxx
= xxxxxx

即將3位數再在前面多寫一次便等如答案. (其實最重要係學識分解功式)

例: 999 X77x13
= 999 x1001
= 999999

Shadow.

👍 0 👎 0

收錄日期: 2021-04-29 19:47:32
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070817000051KK02537

檢視 Wayback Machine 備份