\(a,\Leftrightarrow3m-2+m-2=2\\ \Leftrightarrow m=\dfrac{3}{2}\\ b,\text{PT giao Ox: }y=0\Leftrightarrow x=\dfrac{2-m}{3m-2}\Leftrightarrow OA=\left|\dfrac{m-2}{3m-2}\right|\\ \text{PT giao Oy: }x=0\Leftrightarrow y=m-2\Leftrightarrow OB=\left|m-2\right|\\ \Leftrightarrow S_{AOB}=\dfrac{1}{2}OA\cdot OB=\dfrac{1}{2}\cdot\left|\dfrac{m-2}{3m-2}\cdot\left(m-2\right)\right|=\dfrac{1}{2}\\ \Leftrightarrow\dfrac{\left(m-2\right)^2}{\left|3m-2\right|}=1\\ \Leftrightarrow\left|3m-2\right|=\left(m-2\right)^2\Leftrightarrow\left[{}\begin{matrix}3m-2=m^2-4m+4\left(m\ge\dfrac{2}{3}\right)\\2-3m=m^2-4m+4\left(m< \dfrac{2}{3}\right)\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}m^2-7m+6=0\left(m\ge\dfrac{2}{3}\right)\\m^2-m+2=0\left(vn\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}m=1\\m=6\end{matrix}\right.\)
a: Thay x=1 và y=2 vào (d), ta được:
3m-2+m-2=2
=>4m=6
hay m=3/2
