將第1,2題變分數
1) 1.16161616...........16係循環小數
2)-0.122222222........2係偱環小數
rationlize the following
3) (3√2)/√3
4) √2/√8
5) 5/√2
6) (4√10)/√15
evaluate the following
7) (3√27)x(2√12)x√5
8) 4/√6-√6/3
9) (3√5-√3)(2√3+4√5)
10) (√3-√2)(√3+√2)
ps:√係開方, /係分數, x係乘
中四maths
2009-08-15 5:22 am
回答 (2)
2009-08-15 6:25 am
✔ 最佳答案
(1) Let x = 1.1616...., then 100x = 116.1616....So 100x - x = 115
99x = 115
x = 115/99
(2) Let x = -0.122...., then 10x = -1.222....
So x - 10x = 1.1
-9x = 1.1
x = -1.1/9 = -11/90
(3) (3√2)/√3 = (3√2√3)/3
= √6
(4) √2/√8 = √2/(2√2) = 1/2
(5) 5/√2 = (5√2)/2
(6) (4√10)/√15
= (4√10√15)/15
= (4√150)/15
= (20√6)/15
= (4√6)/3
(7) (3√27) x (2√12) x √5
= (9√3) x (4√3) x √5
= 108√5
(8) 4/√6 - √6/3
= (4√6)/6 - √6/3
= (2√6)/3 - √6/3
= √6/3
(9) (3√5 - √3)(2√3 + 4√5)
= 6√15 - 6 + 60 - 4√15
= 54 - 2√15
(10) (√3-√2)(√3+√2)
= 3 - 2
= 1
參考: Myself
2009-08-15 7:08 am
收錄日期: 2021-04-13 16:47:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090814000051KK02110