（2/3-4/9×3/8）÷7/16
=（2/3-1/6）×16/7
=1/2×16/7
=8/7
9/14×49-9/14÷1/49
=9/14×49-9/14×49
=0
(3/4＋1/2）÷5/8
=5/4×8/5
=2
2/13＋3/4÷9/10＋1/6
=2/13+（5/6+1/6）
=2/13+1
=1又2/13
3/5÷[(3/4-2/3)÷5/6]
=3/5÷[1/12×6/5]
=3/5÷1/10
=6