a) abc = 100 a + 10 b + c; a ≠ 0
abc =3•100+7•10+9
abc = 300 + 70 + 9
abc = 379 → numarul
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b)
324 = a•100+b•10+c
324 = 300 + 20 + 4
324 = 3 • 100 + 2 • 10 + 4 ⇒ a = 3; b = 2 si c = 4
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c)
a3c4 = 5 • 1 000 + b • 100 + 7 • 10 + d ⇒ a = 5; b = 3; c = 7; d = 4
a3c4 = 5 • 1 000 + 3 • 100 + 7 • 10 + 4
5 374 = 5 000 + 300 + 70 + 4