1 целая 2/3+1 целая 1/7

с решением

 

 можно это задание решить двумя способами

              2             1                         2           1                           2*7+1*3

1)   1  ------ + 1 ------ = (1+1)+(-------- + -------) = (1+1)+(-----------------) =

              3             7                         3            7                                 21

          14+3             17

2 + ------------ = 2 --------

             21                21

   или

           2              1            5           8           5*7 + 8*3              35+24

2) 1 ------ + 1 ------- = -------- + ------- = ------------------- = -------------- =

           3               7           3           7                  21                        21

        59               17

 = --------- = 2 --------

        21                21

удачи