maths~急

3a=5b（d應為b之誤）
a=5b/3
3b=2c
c=3b/2
所以，
a:b:c
=5b/3:1:3b/2
=6(5b/3):6(1):6(3b/2)
=10:6:9

did you mean 3a = 5b and 3 b = 2c
i assume it is.....

given 3a=5b & 3b=2c

re-arrange the equations,
3b=2c
=> b = 2/3c
sub b into a
=> 3a=5(2/3c)
=> a=10/9c

sub c into a to find b
b = 2/3(9/10)
b = 3/5

hence, a:b:c = 10/9:2/3:1 in terms of c
therefore, the ratio for a:b:c is equal to
10:6:9

a=3,b=2,c=3,d=3

3a=5b,3b=2c
3a=5b
3a/b=5
a/b=5/3
a:b=5:3 .....(1)

3b=2c
3b/c=2
b/c=2/3
b:c=2:3......(2)

from (1), a:b=5:3=10:6 ....(3)
from(2),b:c=2:3=6:9.......(4)

combine (3) and(4)
a:b:c=10:6:9

設a是5 d是3 b是2 c是3

答案:5:3:2:3