[tex]\it \dfrac{a}{3} = \dfrac{b}{2} \Rightarrow \dfrac{b}{2} = \dfrac{a}{3}|_{\cdot\frac{1}{2}} \Rightarrow \dfrac{b}{4} = \dfrac{a}{6} \ \ \ \ \ (1)
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Dar,\ \ \dfrac{b}{4} = \dfrac{c}{5} \ \ \ \ (2)[/tex]
[tex]\it Din\ \ rela\c{\it t}iile\ \ (1),\ (2) \Rightarrow \dfrac{a}{6} =\dfrac{c}{5}
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Derivez \ \ propor\c{\it t}ia,\ \ schimb\hat{a}nd \ \ mezii, \ \ \c{s}i \ rezult\u{a}:
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\dfrac{a}{c} =\dfrac{6}{5}.[/tex]
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[tex]\it \dfrac{6}{x-5} \in \mathbb{Z} \Leftrightarrow x-5|6\Leftrightarrow x-5\in D_{6}\Leftrightarrow x-5 \in \{\pm1,\ \pm2,\ \pm3,\ \pm6\}
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x-5\ \in \{-6,\ -3,\ -2,\ -1,\ 1,\ 2,\ 3,\ 6\}|_{+5}
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x\in\{-1, \ 2,\ 3,\ 4,\ 6,\ 7,\ 8, \ 11\} = A[/tex]
