Diophantine Equationsmedium
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Vieta jumping is a descent technique: if (x,y)(x, y) solves a symmetric-like Diophantine equation, viewing it as a quadratic in one variable yields two roots. Consider x2+y2xy=3x^2 + y^2 - xy = 3. Verify that (2,1)(2, 1) is a solution. Which of the following is also a solution, obtained by Vieta jumping in xx?