The solutions are x= -½ & y =3.

  Let x be the first speed

     Let y be the second speed

     2x + 3y = 252km --------(1)

       4x + y = 244km --------(2)

From (1): 2x = 252 - 3y --------(3)

substitute (3) into (2): 2(252 - 3y) + y = 244

                                     504 - 6y + y = 244

                                                 260 = 5y

                                                     y = 52

substitute y = 52 into (1): 2x = 252 - 156

                                       x = 48

The two speeds are 48km/h and 52km/h