Fie a, b, c cele trei numere;
b=12+a/4;
c=15+b/2=15+(12+a/4)/2=15+6+a/8=21+a/8;
a+b+c=198;
a+12+a/4+21+a/8=198;
a+33+a/4+a/8=198;
8a+33*8+2a+a=198*8;
11a=198*8-33*8;
11a=8*(198-33);
11a=8*165=8*15*11;
a=8*15*11/11=8*15=120;
a=120;
b=12+120/4=12+30=42
c=21+120/8=21+15=36;
120+42+36=198