ab = numarul de doua cifre
ab = ba + 45
10a + b = 10b + a + 45
10a - a = 10b - b + 45
9a - 9b = 45
9×(a - b) = 45 | : 9
a - b = 5
9 - 4 = 5 => (a; b) = (9; 4)
8 - 3 = 5 => (a; b) = (8; 3)
7 - 2 = 5 => (a; b) = (7; 2)
6 - 1 = 5 => (a; b) = (6; 1)
asadar, ab = 94; 83; 72; 61 .
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94 = 49 + 45
83 = 38 + 45
72 = 37 + 45
61 = 16 + 45
