1. let a,b,c be positive number such that a:b=2:3 and c:b=2:5
a)find a:b:c
b)if c-a=9,find b
2. if 2x=3y=5z,find x:y:z
maths (simple ratio)10marks!!
2007-11-09 9:35 am
回答 (2)
2007-11-09 3:11 pm
✔ 最佳答案
1a)10:15:6b)set
a=10k b=15k c=6k
6k-10k=9
k=-9/4
b=15(-9/4)
=-33.75
2)2x=3y
x:y=3:2
3y=5z
y:z=5:3
x:y:z=15:10:6
2007-11-10 2:02 am
1(a) a:b=2:3 and c:b=2:5
a:b=10:15 and c:b = 6:15
a:b:c = 6:15:10
1(b) c-a=9 ---> c = a + 9
a : c = 6 : 10 = 3 : 5
5a = 3c
5a = 3(a+9)
2a = 27
a = 13.5
2. 2x=3y=5z
2x=3y ---> x/3 = y/2 ---> x:y = 3:2
3y =5z ---> y/5 = z/3 ---> y:z = 5:3
Apply answer in 1, x:y:z = 15:10:6
a:b=10:15 and c:b = 6:15
a:b:c = 6:15:10
1(b) c-a=9 ---> c = a + 9
a : c = 6 : 10 = 3 : 5
5a = 3c
5a = 3(a+9)
2a = 27
a = 13.5
2. 2x=3y=5z
2x=3y ---> x/3 = y/2 ---> x:y = 3:2
3y =5z ---> y/5 = z/3 ---> y:z = 5:3
Apply answer in 1, x:y:z = 15:10:6
參考: self
收錄日期: 2021-04-13 14:23:47
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