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Find all triples of natural numbers (a, b, c) satisfying the system of equations​

Find all triples of natural numbers (a, b, c) satisfying the system of equations​-example-1
User RyanNHG
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1 Answer

24 votes
24 votes

9514 1404 393

Answer:

  • (±7, ±1, ±4)
  • (±13, ±11, ±16)

Explanation:

Solution of the system by the usual means yields the parametric equations ...

(a², b², c²) = (41 +t, t -7, 2t)

Since we want t-7 to be a perfect square, we can let ...

t -7 = n²

t = n² +7

Then the solutions are ...

(a, b, c) = (±√(n²+48), n, ±√(2(n² +7)))

The only integer solutions are for n=±1 and n=±11. Then the 16 possible triples are ...

(±7, ±1, ±4) and (±13, ±11, ±16) . . . where the signs can have any combination

User John Muchow
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