a + b + c = 19 692
b = a x 3 + 6 932
c = a x 2 + 12 700
19 692 - (12 700 + 6 932)=
19 692 - 19 632 = 60
60 = a + 3a + 2a
60 = 6a
a = 60 : 6
a = 10
b = 10 x 3 + 6 932
b = 30 + 6 932
b = 6 962
c = 10 x 2 + 12 700
c = 20 + 12 700
c = 12 720
10 + 6 962 + 12 720 =
= 19 692