A/ $\left \{ {{6x+2y=14} \atop {6x+2y=19}} \right.$ (phương trình sai)
B/ $\left \{ {{x+2y=3} \atop {2x-2y=14}} \right.$
$\left \{ {{3x=17} \atop {x+2y=3}} \right.$
$\left \{ {{x=\frac{3}{17}} \atop {x-y=7}} \right.$
$\left \{ {{x=\frac{3}{17}} \atop {\frac{3}{17}-y=7}} \right.$
$\left \{ {{x=\frac{3}{17}} \atop {y=\frac{-116}{17}}} \right.$