predecesorul nr 7600 este: 7599 9_b+c+d_3+3+3 rezulta 9 9_d+b+c_3+3+3 ...........9 5_a+a+b_1+1+3.............5 7_c+d+a_3+3+1+1..........7 Inlocuim in formula : 1233+3133+3133=7599 Deoarece 9--3+3+3 5--3+2 (1+1) 7--3+3+1 varianta 2.sau 1342+2134+4123=7599
