5分之3×32分之13×39分之8
=3/5×13/32×8/39
=1/20
(10分之9-4分之3)×21分之10
=3/20×10/21
=1/14
7分之2×5分之6-5分之1×7分之2
=2/7(6/5-1/5)
=2/7
9分之5×6分之5+6分之1×9分之5
=5/9(5/6+1/6)
=5/9
7分之8-19分之3-19分之16
=7/8-(3/19+16/19)
=7/8-7/7
=1/7
1又19分之15-17分之2-19分之15
=34/19-15/19-2/7
=1-2/7
=5/7
7分之5+7分之2×4分之3
=5/7+3/14
=10/14+3/14
=13/14
4分之3×7分之3×4×7
=9
17分之15×9分之7-9分之7×17分之6
=7/9(15/17-6/17)
=7/9×9/17
=7/17