6. How many solutions in integers does the equation
Solution
Answer: none.
Solution. Let for some natural numbers and the equality holds. Since ,
the equality can be rewritten as , where . Consider the remainders upon division by 11 of the left and right parts of the equality . Squares can only give remainders of and 9, while fifth powers can only give remainders of 0,1, and 10. But no two of the written remainders add up to the remainder 6, which the number 5001 will have.
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