解: (28/13+28/15)÷2/13+2/15
=(28/13+28/15)*13/2+2/15
=28/13 *13/2 +28/15 *13/2 +2/15
=14+(14*13)/15+2/15
=14+184/15
=14+12又4/15
=26又4/15
(28/13+28/15)÷（2/13+2/15）＝（784/195）÷（56/195）＝14
