原式=（5/6-3/4)*8/3 =5/6*8/3-3/4*8/3 =2/9
(5/6-3/4)÷3/8=5/6×8/3-3/4×8/3=20/9-2=2/9
=（10/12-9/12）/3/8=1/12/3/8=1/288
