Question

rezolvati sistemul :
x-y=6
2y-x=6

Answer 1

[tex]x-y=6 --- x=6+y 2y-x=6--- 2y=6+x 2y=6+6+y 2y=12+y y=12;x=18[/tex] 

Answer 2

$\left \{ {{x-y=6} \atop {2y-x=6}} \right. \ \textless \ =\ \textgreater \ \left \{ {x=6+y} \atop {2y-(6+y)=6}} \right. \ \textless \ =\ \textgreater \ \left \{ {{x-y=6} \atop {2y-6-y=6}} \right. \ \textless \ =\ \textgreater \ \left \{ {{x-y=6} \atop {y-6=6}} \right.$
$\left \{ {{x=6+y} \atop {y=12}} \right. \ \textless \ =\ \textgreater \ \left \{ {{x=6+12} \atop {y=12}} \right. \ \textless \ =\ \textgreater \ \left \{ {x=18} \atop {y=12}} \right.$