Tìm x, biết: 6x^3 + x^2 = 2x.

Trả lời

Lời giải

Ta có: 6x³ + x² = 2x

$\Leftrightarrow \left[ \begin{array}{l}x = 0\\2{\rm{x}} - 1 = 0\\3{\rm{x}} + 2 = 0\end{array} \right.$

$\Leftrightarrow \left[ \begin{array}{l}x = 0\\x = \frac{1}{2}\\{\rm{x}} = \frac{{ - 2}}{3}\end{array} \right.$

Vậy ${\rm{x}} \in \left\{ {0;\frac{1}{2}; - \frac{2}{3}} \right\}$.