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• Question

  Can you fill a `5xx5` table with real numbers such that the sum of each row is positive, and the sum of each column is negative?

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  Topics:

  Combinatorics -> Double Counting Logic -> Reasoning / Logic Proof and Example -> Proof by Contradiction

• Question

  It is known that `a = b+1`. Is it possible that `a^4=b^4`?

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  Topics:

  Arithmetic Algebra -> Equations