1a)(a+2) : (a-3) = 3:1.Find a.
b) (b+3) : (b-4) = 5:2,find b.
2.The radius and the circumference of a circle are r m and 24兀 m respectively.
a)find the value of r.
b)find the area of the circle in terms of 兀.
中二數學~(急急..!10 點!!!!!!!)4月7日前=]
2013-04-06 5:35 am
回答 (2)
2013-04-06 10:21 am
✔ 最佳答案
1.a)
(a + 2) : (a - 3) = 3 : 1
3 x (a - 3) = 1 x (a + 2)
3a - 9 = a + 2
2a = 11
a = 11/2
b)
(b + 3) : (b - 4) = 5 : 2
5 x (b - 4) = 2 x (b + 3)
5b - 20 = 2b + 6
3b = 26
b = 26/3
=====
2.
a)
Circumference of the circle :
2 x π x r = 24π
r = 12
b)
Area of the circle
= π x r²
= π x (12)² cm²
= 144π cm²
參考: 土扁
2013-04-06 9:17 pm
收錄日期: 2021-04-13 19:24:47
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130405000051KK00408