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$s_x=\sqrt{{\frac{1}{n}} \big [(x_1-\overline{x})^2 + (x_2-\overline{x})^2 +\ldots + (x_n-\overline{x})^2 \big ]}$ $\sqrt{v+5}-\sqrt{v^2-7}=0$ $\sqrt[3]{v+5}-\sqrt[2]{v^2-7}=0$ $\dfrac{\tg{(-\frac{\pi}{4})} \cdot{\cotg{(-\frac{\pi}{4})}}} {\sin{(-\frac{3}{2}\pi)} \cdot \cos{(-4\pi)}}$ $x \in A, A \subset B \subseteq C \supset D \supseteq D \ni y$
$\sqrt[3]{v+5}-\sqrt[2]{v^2-7}=0$

$\sqrt[3]{v+5}-\sqrt[2]{v^2-7}=0$