\[\left( x + 7 + \frac{49}{x - 7} \right) \cdot \frac{7 - x}{x^{2}} =\]
\[= \frac{x^{2} - 49 + 49}{x - 7} \cdot \frac{7 - x}{x^{2}} =\]
\[= \frac{- x^{2}(x - 7)}{(x - 7) \cdot x^{2}} = - 1 \Longrightarrow ч.т.д.\ \ \ \ \]
\[x eq 7;0.\]