1)If 2a/b=5(x+y),find the value of 2b/3.
A)20a/3(x+y)
B)3a/5(x+y)
C)4a/15(x+y)
D)2a/15(x+y)
2)Which of the following cannot be factorized?
A) 6ab+6ac+bd+dc
B)6ab-6ac+bd-dc
C)6ab+6ac+bd-dc
D)-6ab+6ac-bd+dc
3)The perimeter of a rectangle is 56cm and the ratio of its length to its width is 4:3.Find the length of its diagonal.
A)5cm
B)20cm
C)28cm
D)40cm
F.2 Mathz (2) (MC)
2007-12-20 7:17 am
回答 (2)
2007-12-20 8:19 am
✔ 最佳答案
1. 2a/b=5(x+y)2a / [5(x+y)]=b
∴2b/3=4a / [15(x+y)]
so the answer is C
2. A. 6ab+6ac+bd+dc=b(6a+d)+c(6a+d)=(6a+d)(b+c)
B. 6ab-6ac+bd-dc=b(6a+d)-c(6a+d)=(6a+d)(b-c)
C. 6ab+6ac+bd-dc=b(6a+d)+c(6a-d)
so the answer is C
3. Let x denote the varible of length and width
2(4x+3x)=56
7x=28
x=4
hence its diagonal is √(162+122)=20
so the answer is B
參考: me
2007-12-20 7:31 am
1.C
2.C
3.C
2.C
3.C
收錄日期: 2021-04-13 14:45:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071219000051KK04218