⇒a+b-c=? (a, b, c ∈ N)

Question

⇒a+b-c=? (a, b, c ∈ N)

Answer 1

{ab = 13,
{bc = 9;
a, b, c ∈ N ⇒ a = 13, b = 1, c = 9
a + b - c = 14 - 9 = 5

Comments

А каким образом?

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А все ясно