To solve this system of equations, we can add the three equations together to eliminate one variable:

а + в + в + с + а + с = 1110 + 1333 + 1557
2(а + в + с) = 4000
а + в + с = 2000

Now we can substitute this value back into the original equations to find the individual values of а, в, and с:

а + в = 1110
а + с = 1557
в + с = 1333

Using the equation а + в = 1110:
а + 2000 - с = 1110
а - с = 1110 - 2000
а - с = -890

Using the equation а + с = 1557:
2000 - в = 1557
в = 2000 - 1557
в = 443

Using the equation в + с = 1333:
443 + с = 1333
с = 1333 - 443
с = 890

Therefore, the values of а, в, and с are:
а = -890
в = 443
с = 890