a) \(pt\Leftrightarrow5-2x-6=8-3x+15\Leftrightarrow x=24\)
b) \(pt\Leftrightarrow\left(x-3\right)\left(x^2-2\right)+\left(x-3\right)\left(x+2\right)=0\)
\(\Leftrightarrow x\left(x-3\right)\left(x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-1\end{matrix}\right.\)
c) \(pt\Leftrightarrow x\left(5x-8\right)+\left(5x-8\right)=0\Leftrightarrow\left(5x-8\right)\left(x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{8}{5}\\x=-1\end{matrix}\right.\)
d) \(pt\Leftrightarrow\dfrac{6\left(2x-5\right)-8\left(3x-2\right)-3\left(5x-1\right)}{48}=0\Leftrightarrow-27x-11=0\Leftrightarrow x=-\dfrac{11}{27}\)
e) \(pt\Leftrightarrow\dfrac{\left(x+1\right)^2-4\left(x-1\right)+2x-2x^2-4}{\left(x-1\right)\left(x+1\right)}=0\Leftrightarrow-x^2+1=0\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)
