ABC is a triangle. The length of AB is (x-1) , BC is (x+3), CA is (x+1).
If AB : BC : CA = 3 : 5 : 4, find x and the perimeter of ABC.
中一數學問題
2007-04-08 7:34 pm
回答 (2)
2007-04-08 7:42 pm
✔ 最佳答案
AB : BC = 3 : 5(x-1) : (x+3) = 3 : 5
5(x-1) = 3(x+3)
5x-5 = 3x+9
2x = 14
x = 7
The perimeter of ABC
=(7-1) + (7+3) + (7+1)
=6 + 10 + 8
=24
參考: by My Maths
2007-04-09 6:45 pm
AB:BC= 3:5
(x-1) :(x+3) = 3:5
(x-1) /(x+3) = 3/5
3(x+3) = 5(x-1)
3x+9=5x-5
5x-3x=9+5
2x=14
x=7
AB=7-1
=6
BC=7+3
=10
CA=7+1
=8
the perimeter of ABC=6+10+8
=24
(x-1) :(x+3) = 3:5
(x-1) /(x+3) = 3/5
3(x+3) = 5(x-1)
3x+9=5x-5
5x-3x=9+5
2x=14
x=7
AB=7-1
=6
BC=7+3
=10
CA=7+1
=8
the perimeter of ABC=6+10+8
=24
收錄日期: 2021-04-13 00:43:02
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https://hk.answers.yahoo.com/question/index?qid=20070408000051KK01186