\left \{ {{x+y=3\atop 2x+y=3\right

\left \{ {{x+y=3\atop 2x+y=3\right. \left \{ {{3x+3y=9\atop x+y=2\right. \left \{ {{3x+2y=3\atop 4x+2=0\right. \left \{ {{3x+3y=9\atop x+y=2\right.\left \{ {{3x+2y=3\atop 4x+2=0\right.