8/7*38+43*8/7-8/7 8/9*14/5*10/7 6/39*13/5-6/1 4/9*（3/1-4/1）

8/7*38+43*8/7-8/7
=(8/7)*(38+43-1)
=(8/7)*80
=70
8/9*14/5*10/7
=(8/9)*(14/7)*(10/5)
=(8/9)*(2/1)*(2/1)
=32/9
6/39*13/5-6/1
=(6/5)*(39/13)-6/1
=(6/5)*(3/1)-18/3
=18/5-18/3
=18/2
=9/1
4/9*（3/1-4/1）
=(4/9)*(3/1)-(4/9)*(4/1)
=4/3-(4/9)*(4/1)
=1-4/1-(4/9)*(4/1)
=1-(4/1)*(1+4/9)
=1-(4/1)*(4/13)
=1-16/13
=16/3