Giải thích các bước giải:
a) $x(3x - 4) - 6x + 8 = 0$
$\Leftrightarrow x(3x - 4) - 2(3x - 4) = 0$
$\Leftrightarrow (3x - 4)(x - 2) = 0$
$\Leftrightarrow \left[ \begin{array}{l}x = \dfrac{4}{3}\\x = 2\end{array} \right.$
b) $3x - 15 = 2x(x - 5)$
$\Leftrightarrow 3x - 15 = 2x^{2} - 10x$
$\Leftrightarrow 2x^{2} - 13x + 15 = 0$
$\Leftrightarrow x(2x - 3) - 5(2x - 3) = 0$
$\Leftrightarrow 2x^{2} - 3x - 10x + 15 = 0$
$\Leftrightarrow (2x - 3)(x - 5) = 0$
$\Leftrightarrow \left[ \begin{array}{l}x = \dfrac{3}{2}\\x = 5\end{array} \right.$
