Cyclic inequality, need help

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$x+\frac{1}{y}=10$; $y+\frac{1}{z}=10$; $z+\frac{1}{x}=10$;

What is the highest possible value of z?

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There are 2 best solutions below

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$x=\frac{1}{10-z}$ and $1=y\left(10-\frac{1}{10-z}\right)$,

which gives $y=\frac{10-z}{99-10z}$.

Hence, $$\frac{(10-z)z}{99-10z}+1=10z$$ or $$z^2-10z+1=0,$$ which gives the answer: $5+\sqrt{24}$.

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As you put it, it's an equation with two solutions. The one with the highest z has $z=5+2\sqrt 6$