Odpowiedzi

2010-03-09T16:58:53+01:00
0,5x - 0,25y = 4
0,25x + y = 7 / * (-2)

0,5x - 0,25y = 4
-0,5x - 2y = -14

0,5x-0,25y-0,5x-2y = 4-14

-2,25y = -10 / :-2,25

y=4,44

y=4,44
0,25x - 4,44 = 7

0,25x = 7-4,44
0,25x=2,56 / :0,25
x=10,24

2010-03-09T17:09:27+01:00
0,5x-0,25y=4
0,25x+y=7

y=7-1/4x
1/2x-1/4(7-1/4x)=7
1/2x-7/4+1/16x=7
8/16x+1/16x=7+7/4
9/16x=28/4+7/4
9/16x=35/4
x=35/4:9/16
x=35/4*16/9
x=140/9
y=7-1/4*140/9=7-35/9=63/9-35/9=28/9

Spr.
1/4*140/9+28/9=35/9+28/9=7
pozdrawiam:)
2010-03-09T17:11:21+01:00
0,5x - 0,25y = 4
0,25x + y = 7

1/2x - 1/4y = 4
y = 7 - 1/4x

1/2x - 1/4(7-1/4x) = 4
y = 7 - 1/4x

1/2x - 7/4 + 1/8x = 4
y = 7 - 1/4x

5/8x = 23/4 /*8
y = 7 - 1/4x

5x = 184/4 / :5
y = 7-1/4x

x = 184/20
y = 7 - 1/4x

x = 184/20
y = 7 - 1/4 * 184/20

x = 184/20
y = 7- 46/20

x = 9 i 1/5
y = 4 i 7/10