Răspuns :
n : 6 = 13 rest r ⇒ n =6·13 +r, unde r ∈ {0, 1, 2, 3, 4, 5}
n= 78 + r
n∈ {78, 79, 80, 81, 82, 83}
x : 6 = 13
x = 6 * 13
x = 78 rest 0
79 : 6 = 13 rest 1
80 : 6 = 13 rest 2
81 : 6 = 13 rest 3
82 : 6 = 13 rest 4
83 : 6 = 13 rest 5
78, 79, 80, 81, 82, 83
x = 6 * 13
x = 78 rest 0
79 : 6 = 13 rest 1
80 : 6 = 13 rest 2
81 : 6 = 13 rest 3
82 : 6 = 13 rest 4
83 : 6 = 13 rest 5
78, 79, 80, 81, 82, 83