[tex]3 - 7x \neq 0 \iff x \neq \frac{3}{7} \\D: x \in \mathbb{R} \setminus \{ \frac{3}{7} \}[/tex]
[tex]\frac{14x - 6}{3 - 7x} = -5x \ \ \ \ \ | \cdot (3 - 7x)\\14x - 6 = -5x(3 - 7x)\\14x - 6 = -15x + 35x^2 \ \ \ \ \ | - 14 x + 6\\35x^2 - 29x + 6 = 0\\\Delta = (-29)^2 - 4 \cdot 35 \cdot 6 = 1\\\sqrt{\Delta} = 1 \lor \sqrt{\Delta} = -1\\x_1 = \frac{29 + 1}{70} = \frac{3}{7} \\x_1 \notin D\\x_2 = \frac{29 - 1}{70} = \frac{2}{5} \\[/tex]
Rozwiązaniem równania jest [tex]x = \frac{2}{5}[/tex].
