9/2:9/7=4/3:(4-x)

问题描述:

9/2:9/7=4/3:(4-x)
9/2是各2分之9⋯

9/2:9/7=4/3:(4-x)
9/2(4-x)=12/7
18-9x/2=12/7
9x/2=114/7
x=114/7*2/9
x=76/21