$\displaystyle \begin{cases} y=-2x+8\\ y=- \frac{3}{2}x+ \frac{13}{2} \end{cases}$\displaystyle \begin{cases} y=-2x+8\\ y=- \frac{3}{2}x+ \frac{13}{2} \end{cases}

$\displaystyle \begin{cases} y=2x-4\\ y=- \frac{1}{2}x+ \frac{7}{2} \end{cases}$\displaystyle \begin{cases} y=2x-4\\ y=- \frac{1}{2}x+ \frac{7}{2} \end{cases}

$\displaystyle \begin{cases} y=x-1\\ y= \frac{1}{2}x+ \frac{1}{2} \end{cases}$\displaystyle \begin{cases} y=x-1\\ y= \frac{1}{2}x+ \frac{1}{2} \end{cases}

$\displaystyle \begin{cases} y=3x-7\\ y=- \frac{2}{3}x+4 \end{cases}$\displaystyle \begin{cases} y=3x-7\\ y=- \frac{2}{3}x+4 \end{cases}