已知b分之a=3比2,a分之c=6比5.求b分之c=?（2）已知a比b=9比7,b比c=5比3.求a

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a/b=3/2 b=a*2/3
a/c=6/5 c=a*5/6
b/c= (2/3)/(5/6)=4/5
a:b=9:7=45:35
b:c=5:3=35:21
a:b:c=45:35:21
======以下答案可供参考======
供参考答案1:
(1)a/b=3/2 & c/a=6/5
a/b*c/a=3/2*6/5 --> c/b=9/5
(2)a/b=9/7 & b/c=5/3
a=9b/7
b=5c/3
如果c=1,
b=5/3a=9/7*5/3=15/7
a:b:c=15/7:5/3:1=45:35:21
供参考答案2:
(1)a/b=3/2 c/a=6/5
a/b×c/a=3/2×6/5→c/b=9/5
(2)a/b=9/7 b/c=5/3
a/b=9×5/7×5=45/35 b/c=5×7/3×7=35*21
a/b/c=45/35/21