D : I = c r
c = I : 4 ==> I = 4×c
r = c : 2
I + c + r = 99
inlocuim in ultima relatie in functie de c
4×c + c + c : 2 = 99
5 × c + c : 2 = 99 |×2
10 × c + c = 198
11 × c = 198
c = 198 : 11
c = 18 (catul)
I = 4 × 18 = 72 (impartitorul)
r =18 : 2 = 9 (restul)
D = I × c + r = 72 × 18 + 9 = 1296 + 9 =
= 1 305 (deimpartitul)
1 305 : 72 = 18 rest 9