Răspuns :
a+b+c=999
a+b=656
b+c=504
656+c=999
c=999-656=343
a+504=999
a=999-504=495
b=999-343-495=161
495+161+343=999
a+b=656
b+c=504
656+c=999
c=999-656=343
a+504=999
a=999-504=495
b=999-343-495=161
495+161+343=999
A+B+C=999
A+B=656
B+C=504
656+C=999
C=999-656
C= 343
B+343=504
B=504-343
B=161
A+161=656
A=656-161
A=495
A+B=656
B+C=504
656+C=999
C=999-656
C= 343
B+343=504
B=504-343
B=161
A+161=656
A=656-161
A=495