Lời giải:
$2x^2-7x+6=0$
$\Leftrightarrow (2x^2-4x)-(3x-6)=0$
$\Leftrightarrow 2x(x-2)-3(x-2)=0$
$\Leftrightarrow (x-2)(2x-3)=0$
$\Leftrightarrow x-2=0$ hoặc $2x-3=0$
$\Leftrightarrow x=2$ hoặc $x=\frac{3}{2}$
2x2 - 7x + 6 = 0
\(\Leftrightarrow\) 2x2 - 4x - 3x + 6 = 0
\(\Leftrightarrow\) (2x2 - 4x) - (3x - 6) = 0
\(\Leftrightarrow\) 2x(x - 2) - 3(x - 2) = 0
\(\Leftrightarrow\) (x - 2)(2x - 3) = 0
\(\Leftrightarrow\) \(\left[{}\begin{matrix}x-2=0\\2x-3=0\end{matrix}\right.\) \(\Leftrightarrow\) \(\left[{}\begin{matrix}x=2\\x=\dfrac{3}{2}\end{matrix}\right.\)
S = \(\left\{2,\dfrac{3}{2}\right\}\)
