Respuesta :

This is how I would solve it:

1st # = x                 4(x+1)=3x+18
2nd # = x+1              4x+4=3x+18
                                     4x=3x+14
                                       x=14

To check: 15x4=60; 60-42=18.       1st # = 14; 2nd # = 15.