Răspuns:
b)
x-2y=6
2x+2y=0
_______
3x / = 6 =>x=2 =>y=(-2)
c)
3x-2y=1 |•(-2)
5x-4y=(-1)
-6x+4y=(-2)
5x-4y=(-1)
_________
-x / = (-3) =>x=3 =>y=4
d)
6x-y=12 |•3
4x+3y=30
18x-3y=36
4x+3y=30
________
22x / = 66 =>x=3 =>y=6
e)
-3x-4y=10 |•2
2x+3y=(-6) |•3
-6x-8y=20
6x+9y=(-18)
_________
/ y=2 =>x=(-6)
f)
5x-9y=22 |•4
-3x+4y=(-16) |•9
20x-36y=88
-27x+36y=(-144)
_____________
-7x / = -56 =>x=8 =>y=2