x/2 >20/x>x/1,7
[tex]\it\ I)\ \dfrac{x}{2}\ \textgreater \ \dfrac{x}{1,7} \Rightarrow \dfrac{x}{2}-\dfrac{^{10)}x}{\ 1,7} \ \textgreater \ 0 \Rightarrow\dfrac{x}{2}-\dfrac{10x}{17} \ \textgreater \ 0 \Rightarrow \dfrac{17x-20x}{34}\ \textgreater \ 0 \Rightarrow
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\Rightarrow \dfrac{-3x}{34} \ \textgreater \ 0 \Rightarrow -3x\ \textgreater \ 0 |_{\cdot (-1)} \Rightarrow 3x\ \textless \ 0 \Rightarrow x\ \textless \ 0\ \ \ \ (1)[/tex]
[tex]\it \ II)\ \dfrac{x}{2}\ \textgreater \ \dfrac{20}{x}|_{\cdot(-1)} \Rightarrow \dfrac{-x}{2}\ \textless \ \dfrac{20}{-x} \Rightarrow x^2 \ \textless \ 40 \ \ \ \ \ (2)[/tex]
[tex]\it\ III)\ \dfrac{20}{x} \ \textgreater \ \dfrac{x}{1,7}|_{\cdot(-1)} \Rightarrow \dfrac{20}{-x} \ \textless \ \dfrac{-x}{1,7}|_{\cdot(-1)} \Rightarrow 20\cdot1,7\ \textless \ (-x)\cdot(-x) \Rightarrow
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\Rightarrow 34\ \textless \ x^2 \Rightarrow x^2\ \textgreater \ 34 \ \ \ \ (3)[/tex]
[tex]\it (2),\ (3) \Rightarrow 34\ \textless \ x^2\ \textless \ 40 \stackrel{(1)}\Longrightarrow} x=-6.[/tex]
