Răspuns :

1 a) 

[tex] \left \{ {{2x-3y=0} \atop {2x+3y=2}} \right. [/tex]
[tex] \left \{ {{4x=2} \atop {2x+3y=2}} \right. [/tex]
[tex] \left \{ {{x=0,5} \atop {1+3y=2}} \right. [/tex]
[tex] \left \{ {{x=0,5} \atop {3y=1}} \right. [/tex]
[tex] \left \{ {{x=0,5} \atop {y=1/3}} \right. [/tex]

b) 
[tex] \left \{ {{x-2y=-1} \atop {2x-y=-5/4}} \right. [/tex]
[tex] \left \{ {{x=2y-1} \atop {3x-3y=-9/4}} \right. [/tex]
[tex] \left \{ {{x=2y-1} \atop {6y-3-3y=-9/4}} \right. [/tex]
[tex] \left \{ {{x=2y-1} \atop {3y=-9/4+3}} \right. [/tex]
[tex] \left \{ {{x=0.5} \atop {y=0.75}} \right. [/tex]