x , y , z is primes numbers solve : x^3=x^2+y^2+z^2
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One obvious solution: x=y=z=3.
thak you but how?
Originally Posted by dhiab x , y , z is primes numbers solve : x^3=x^2+y^2+z^2 Use congruence mod 3. [1] x = 0 (mod 3) then x = 3 and y^2 + z^2 = 18 which implies y = z = 3 [2] x = 1 (mod 3) then ...... [3] x = 2 (mod 3) then ......
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