Odpowiedź i szczegółowe wyjaśnienie:
[tex]\left \{ {{2x+y=6} \atop {2y=3}} \right. \\\\\left \{ {{2x+y=6} \atop {y=\frac32}} \right. \\\\\left \{ {{2x+\frac32=6} \atop {y=\frac32}} \right. \\\\\left \{ {{2x=6-\frac32} \atop {y=\frac32}} \right. \\\\\left \{ {{2x=\frac{12}{2}-\frac32} \atop {y=\frac32}} \right. \\\\\left \{ {{2x=\frac92\ /:2} \atop {y=\frac32}} \right. \\\\\left \{ {{x=\frac94} \atop {y=\frac32}} \right.[/tex]
[tex]\left \{ {{3z-y=2\ /\cdot(-3)} \atop {z-3y=1}} \right. \\\\\left \{ {{-9z+3y=-6} \atop \underline{z-3y=1}} \right.\\\\-9z+z=-6+1\\-8z=-5\ /:(-8)\\z=\frac{5}{8}[/tex]
