Răspuns :
Răspuns:
Explicație pas cu pas:
a) 2x-3y=7 (-2) -4x+6y=-14
4x+4y=4 4x+4y=4
.........................
10y=-10 y=-1 x=1-y=1+1=2
x=2
y=-1
b)2x+4y=2 (-2) -4x-8y=-4
4x+6y=0 4x+6y=0
.............................
-2y=-4 y=2 4x+12=0 x=-3
x=-3
y=2
d)6x-2y=-14 6x-2y=-14
7x+y=-13 (2) 14x+2y=-26
.........................
20x=-40 x=-2 -14+y=-13 y=1
x=-2
y=1
c)4x-3y=20 (5) 20x-15y=100
5x+2y=2 (-4) -20x-8y=-8
.....................
-23y=92 y=-4 4x+12=20 4x=8 x=2
x=2
y=-4
e)2x+y=-2 (2) 4x+2y=-4
3x+2y=-1 (-1) -3x-2y=1
........................
x=-3 -6+y=-2 y=4
x=-3
y=4