5分之1×27+5分之3×4
=27/5+12/5
=39/5
17分之1×9分之7+17分之5
=1/17×(9分之7+5)
=1/17×9分之52
=52/153
4分之3×5分之1+4分之3×5分之4
=4分之3×(5分之1+5分之4)
=3/4