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2009-12-08T14:22:13+01:00
A)
-x+y=5
x+y=5

2y=10 /2
y=5

y=5
x+5=5

y=5
x=5-5

y=5
x=0

b) x-2y=4
-x+3y=0

y=4
x-2*4=4

y=4
x-8=4

y=4
x=12

c)
3u+2v=2 /*-2
5u+4v=6

-6u-4v=-4
5u+4v=6

u=2
3*2+2v=2

u=2
6+2v=2

u=2
2v=-3 / :2

u=2
v= -1,5

d)
x-3y=5
3x+y=-5 /*3

x-3y=5
9x+3y=-15

10x=-10 /:10
x=-1

x=-1
-1*3+y=-5

x=-1
-3+y=-5

x=-1
y=-2
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Najlepsza Odpowiedź!
2009-12-08T14:26:05+01:00
A) - x+y = 5
x + y = 5
...........
2y=10/2
y=5
x + y = 5
x=5-y
x=5-5
x=0

b) x - 2y = 4
- x + 3y = 0
..............
y=4
x - 2y = 4
x=4+2y
x=4+2×4
x=4+8
x=12

c) 3u + 2v = 2/×(-2)
5u + 4v = 6

-6u-4v=-4
5u + 4v = 6
..........
-u=2
u=-2
3u + 2v = 2
2v=2-3u
2v=2-3×(-2)
2v=2+6
2v=8/÷2
v=4

d) x - 3y = 5/×(-3)
y + 3x = -5

9y-3x=-15
y + 3x = -5
..............
10y=-20/÷ 10
y=-2
x - 3y = 5
x=5+3y
x=5+3×(-2)
x=5-6
x=-1
4 3 4
2009-12-08T14:36:03+01:00
-x+y=5
a
x+y=5


y+y=5+5
2y=10
y=2

x+y=5
x+2=5
x=5-2
x=3


x=3
y=2


b

x-2y=4
-x+3y=0

-2y+3y=4
y=4

x-2y=4
x-2×4=4
x-8=4
x=4+8
x=12

x=12
y=4

c

3u+2v=2 } -2
5u+4v=6

-6u-4v=-4
5u+4v=6

-6u+5u=-4+6
-u=2 }-1
u=-2

3×{-2}+2v=2
-6+2v=2
2v=2+6
2v=8
v=4

u=-2
v=4

d

x-3y=5
y+3x=-5

x-3y=5 }-3
3x+y=-5

-3x+9y=-15
3x+y=-5

9y+y=-15-5
10y=-20
y=-2

x-3y=5
x-3×{-2}=5
x+6=5
x=5-6
x=-1

x=-1
y=-2

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