[imath]PT \leftrightarrow \cfrac{3}{\cfrac{6}{x} + 1} - \cfrac{5}{\cfrac{10}{x} - 1} = x \\ x \notin \{ -6, 0, 10 \} \\ \leftrightarrow \cfrac{3x}{6 + x} - \cfrac{5x}{10 - x} = x \\ \leftrightarrow \cfrac{-8x^2}{-x^2 + 4x + 60} = x \\ \leftrightarrow x(x^2 - 12x - 60) = 0 \\ \rightarrow x = 6 \pm \sqrt{96}[/imath]