Odpowiedź:
x + y = 2
x -y = 4
2x = 6 / : 2
x= 3
× + y = 2
3 + y = 2
y = 2 - 3
y = -1
spr .3 + (-1)=2
2× + y = 4
× - y = 1
3 × = 5 / : 3
× = 5/3
2× + y = 4
y = 4 -( 2/1×5/3
y = 4 - 10/3
y = 48/12 - 40/12
y = 8/12
y = 2/3
spr . 2x+y = 4
2/1 × 5/3 + 2/3 =4
10/3 + 2/3 = 12/3 = 4