Odpowiedzi

2009-09-13T14:01:17+02:00
{x+2y=-8
{-5x-2y=-12 | +
-4x=-20 / :(-4)
x=5
obl. y
x+2y=-8
5+2y=-8
2y=-8-5
2y=-13 /:2
y=-7,5
x=5


{2x+y+1=0 / *(-1)
{3x+y-16=0
-2x-y-1=0
3x+y-16=0
x-17=0
x=17
obl. y
2x+y+1=0
2*17+y+1=0
34+y+1=0
y=-35
x=17






2009-09-13T14:03:09+02:00
{x+2y=-8
{-5x-2y=-12

x+2y-5x-2y = -8-12
-4x = -20 /:(-4)
x = 5

5 + 2y = -8
2y = -8-5
2y = -13 /:2
y = -¹³/₂
y = -6¹/₂



{2x+y+1=0 / *(-1)
{3x+y-16=0

{-2x-y-1 = 0
{3x+y-16=0

{-2x-y=1
{3x+y = 16

-2x-y+3x+y = 16+1
x = 17

3*17+y = 16
51+y=16
y = 16-51
y = -35

Mam nadzieję, że pomogłam :)
2009-09-13T14:06:49+02:00
{x+2y=-8
{-5x-2y=-12

x=-8-2y
-5x-2y=-12

x=-8-2y
-5(-8-2y)-2y=-12

x=-8-2y
40+10y-2y=-12

x=-8-2y
8y=-54/8

x=-8-2y
y=-6¾

x=-8-2*(-6¾)
y=-6¾

x=-8+13½
y=-6¾

x=5½
y=-6¾





{2x+y+1=0 / *(-1)
{3x+y-16=0

{-2x-y-1 = 0
{3x+y-16=0

{-2x-y=1
{3x+y = 16
----------------
x = 17

3*17+y = 16
51+y=16
y = 16-51
y = -35
x=17