Odpowiedzi

2010-02-01T19:17:39+01:00
1.
3m + n = 9 |*5
2m - 5n = -11

15m + 5n = 45
2m - 5n = -11
____
17m=34 |:17
m=2

3*2+n=9
n=9-6
n=3

2.
2x + 2 = 3y
y = 10 - 2x

2x-3y=-2
y+2x=10 |*3

2x-3y=-2
3y+6x=30
_____
8x=28 |:8
x=3,5

y+2*3,5=10
y=10-7
y=3
2010-02-01T19:18:50+01:00
1)3m+n=9
2m-5n=-11

n=9-3m
2m- 45-15m=-11

n=9-3m
17m=34

n=9-3m
m=2

n=3
m=2

2)2x+2=3y
y=10-2x

2x+2=30-6x
y=10-2x

8x=32
y=10-2x

x=3,5
y=3
2010-02-01T19:23:15+01:00