Respuesta :

[tex] \left \{ {{x+y=3\:(I)} \atop {x-y=1\:(II)}} \right. [/tex]

by elemination

[tex]\left \{ {{x+\diagup\!\!\!\!y=3} \atop {x-\diagup\!\!\!\!y=1}} \right.[/tex]
[tex]\left \{ {{x=3} \atop {x=1}} \right.[/tex]
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[tex]2x = 4[/tex]
[tex]x = \frac{4}{2} [/tex]
[tex]\boxed{x = 2}[/tex]


Replace the found value of "x", to find the value of "y"
[tex]x+y=3\:(I)[/tex]
[tex]2 + y = 3[/tex]
[tex]y = 3 - 2[/tex]
[tex]\boxed{y = 1}[/tex]

Answer:
X = 2
Y = 1