Odpowiedzi

2009-12-13T18:12:36+01:00
1)
½×-2y=8 /*2
2×+5y=6

x-4y=16
2x+5y=6

x=16+4y
2(16+4y)+5y=6

x=16+4y
32+8y+5y=6

x=16+4y
13y=-26

x=16+4y
y=-2

x=16-8
y=-2

x=8
y=-2

2)
0,4x+0,3y=1,4 /*10
0,1x+3y=2,3 /*10

4x+3y=14
x+30y=23

4x+3y=14
x=23-30y

4(23-30y)+3y=14
x=23-30y

92-120y+3y=14
x=23-30y

-117y=-78
x=23-30y

y=2/3
x=23-[(2/3)*30]

x=3
y=2/3





Najlepsza Odpowiedź!
2009-12-13T18:16:24+01:00
Zad1.
½×-2y=8 /*2
2×+5y=6

x -4y = 16
2x +5y = 6

x = 16 + 4y
2(16 +4y ) + 5y = 6

x = 16 + 4y
32 +8y +5y = 6

x = 16 + 4y
13y = 6-32

x = 16 + 4y
13y = -26

x = 16 + 4*(-2)
y = (-26) : 13

x = 16 -8
y = -2

x = 8
y = -2


Zad.2
0,4x+0,3y=1,4 /*10
0,1x+3y=2,3 /*10

4x +3y = 14
x +30y = 23

4x +3y = 14
x = 23 -30y

4*( 23 -30y ) + 3 y = 14
x = 23-30y

92 -120y +3y = 14
x = 23-30y

-117y = 14-92
x = 23 - 30y

-117 y = -78
x = 23 - 30y

y = (-78): (-117)
x = 23 -30*2/3

y = 2/3
x = 23- 20

y = 2/3
x = 3