Odpowiedzi

Najlepsza Odpowiedź!
2009-09-28T17:56:34+02:00
1.
x-2y=-2
x+2y=0

2x=-2 / :2
x=-1

-1+2y=0
2y=1 /:2
y=1/2

2.
2x-y-=0
x+y=-3

3x=-3 / :3
x=-1
-1+y=-3
y=-2
2009-09-28T18:00:26+02:00
X-2y = -2| + 2y
x = -2 + 2y

x+2y=0 |-2y
x = 0-2y
0-2y=-2+2y |+2
2-2y = 2y |+2y
2 = 4y | :4
½ = y

x= -2 + 2y = -2 + 1 = -1
x=-1 y=½

2. 2x-y-=0 | + y
2x = y
x+y=-3 = x+2x= -3
3x = -3 | :3
x = -1
y = 2x = 2*-1 = 1

x= -1 y= 1