a+b+c=486
b/a =3 R 18 ;b =3a +18
c/b =2 R12 ; c =2b +12 ; c =2(3a+18)+12 ;c =6a+36+12 ;c =6a +48 inlocuim pe b si c in prima relatie
a +3a +18 +6a +48 =486
10a =486 -18-48
10a =420
a =42
b =3a +18
b =3*42 +18
b =126+18
b =144
c =2b +12
c =2*144 +12
c =288+12
c =300
42+144+300 =486