26×39分之14+13×39分之16
=39分之13×28+39分之13×16
=39分之13×(28+16)
=3分之1×44
=3分之44
2.8×(7分之1+28分之3)
=2.8×7分之1+2.8×28分之3
=0.4+0.3
=0.7