[tex] \left \{ {{x+y=4} \atop {3x+y=6}} \right. [/tex] inmultim prima cu (-1)
[tex] \left \{ {{-x-y=-4} \atop {3x+y=6}} \right. [/tex]
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-x-y+3x+y=-4+6
2x=2
x=2:2
x=1
[tex] \left \{ {{x+y=4} \atop {x=1}} \right. [/tex] inlocuim x⇒y=4-1⇒y=3
