Răspuns :
2x-y=3
x+2y=4
x=4-2y
2(4-2y)-y=3
8-4y-y=3
5y=5
y=1
x=4-2*1=2
metoda 2
2x-y=3
x+2y=4 inmultim cu -2
2x-y=3
-2x-4y=-8
le adunam membru cu membru
0-5y=3-8
-5y=-5
y=1
x=4-2*1=2
x+2y=4
x=4-2y
2(4-2y)-y=3
8-4y-y=3
5y=5
y=1
x=4-2*1=2
metoda 2
2x-y=3
x+2y=4 inmultim cu -2
2x-y=3
-2x-4y=-8
le adunam membru cu membru
0-5y=3-8
-5y=-5
y=1
x=4-2*1=2