[tex]a)\\\\\begin{cases}2x-y =-4\\ x+y =1 \end{cases}\\\\\begin{cases}y=2x+4\\ y =-x+1 \end{cases}\\\\b)\\\\\begin{cases}2x-4y =-4\\x-2y=-6 \end{cases}\\\\\begin{cases} -4y =-2x-4\ \ |:(-4)\\ -2y=-x-6:(-2) \end{cases}[/tex]
[tex]\begin{cases} y = \frac{1}{2}x-1\\ y= \frac{1}{2}x+3 \end{cases}\\\\c)\\\\\begin{cases} x-3y =-3\\2x-6y=-6 \end{cases}\\\\\begin{cases} -3y =-x-3\ \ |:(-3)\\ -6y=-2x-6\ \ |:(-6)\end{cases}\\\\\begin{cases} y =\frac{1}{3}x +1\\ y=\frac{1}{3}x+1 \end{cases}[/tex]
