(a+3):(a+5):b=3:4:7
求a的值
ps:請詳細解釋,,,比和率我吾系幾得
中一數學題,,,help
2008-06-19 1:18 am
回答 (3)
2008-06-19 1:27 am
✔ 最佳答案
(a+3):(a+5):b=3:4:7that means
(a+3):(a+5)=3:4
(a+3)/(a+5)=3/4
4(a+3)=3(a+5)
4a+12=3a+15
a=3
And then
(a+5):b=4:7
(3+5):b=4:7
8/b=4/7
7x8=4b
4b=56
b=14
if a:b:c=x:y:z
a/x=b/y
b/c=x/z
a:b=a/b
2008-06-19 1:32 am
(a+3)÷3 = (a+5)÷4
4a+12 = 3a + 15
a = 3
4a+12 = 3a + 15
a = 3
2008-06-19 1:27 am
a+3 3
------=----
a+5 4
4(a+3)=3(a+5)
4a+12=3a+15
a=3
a+5 4
------=----
b 7
7(3+5)=4b
b=14
------=----
a+5 4
4(a+3)=3(a+5)
4a+12=3a+15
a=3
a+5 4
------=----
b 7
7(3+5)=4b
b=14
收錄日期: 2021-04-25 16:36:37
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