Răspuns :
a + b + c = 243 → suma
a : c = 12 rest 7
a = 12 × c + 7
b : c = 5 rest 2
b = 5 × c + 2
a + b + c = 243
( 12 × c + 7 ) + ( 5 × c + 2) + c = 243
( 12 × c + 5 × c + c ) + ( 7 + 2) = 243
18 × c = 243 - 9
c = 234 : 18
c = 13 → al treilea nr.
a = 12 × 13 + 7 = 156 + 7 = 163 → primul numar
b = 5 × 13 + 2 = 65 + 2 = 67 → al doilea numar
Verific: 163 + 67 + 13 = 163 + 80 = 243 → suma celor 3 numere
Raspuns: 163; 67 si 13
a+b+c=243
a/c=cat12rest7, a=12c+7 (teorema impartirii cu rest)
b/c=cat5res2, b=5c+2, inlocuim a si b in suma
12c+7+5c+2+c=243, 18c=243-9=234, c=234/18=13
a=12*13+7=163, b=5*13+2=67