x除以11/18=3/4
x=(3/4)*(11/18)
x=11/24
2/3x=8/15
x=(8/15)*(3/2)
x=4/5
3/7x +1/14x=9
6/14x+1/14x=9
7/14x=9
1/2x=9
x=9*2
x=18