A:
{x+y=2
{x-y=0
B:
{-x+y=5
{x+y=5
C:
{5x+3y=0
{-x-2y=7
D:
{3s+5t=-6
{1,5s-2t=-3
E:
{x-3y=5
{y+3x=-5

Te kalmerki co sa dwie to powinna byc jedna i duza jak cos :P; d i z gory dzieki ;D i jak moze ktos to jak najszybciej:* bo bede miala 1 na polrocze ; d

2

Odpowiedzi

Najlepsza Odpowiedź!
2010-01-05T18:44:54+01:00
A:
{x+y=2
{x-y=0

2x=2 ||:2
x=1

{x+y=2 ||*-1
{x-y=0

-x-y=-2
x-y=0

-2y=-2 ||:-2
y=1



B:
{-x+y=5
{x+y=5

2y=10 ||:2
y=5

{-x+y=5 ||*-1
{x+y=5

x-y=-5
x-y=5

2x=0 ||:2
x=0


C:
{5x+3y=0
{-x-2y=7 ||*5

5x+3y=0
-5x-10y=35

-7y=35 ||:(-7)
y=-5

{5x+3y=0 ||*2
{-x-2y=7 ||*3

10x+6y=0
-3x-6y=21

7x=21 ||:7
x=3


D:
{3s+5t=-6
{1,5s-2t=-3 ||*(-2)

3s+5t=-6
-3s+4t=6

9t=0 ||*9
t=0

{3s+5t=-6 ||*2
{1,5s-2t=-3 ||*5

6s+10t=-12
7,5s-10t=-15

0,5s=-3 ||*2
s=-6

E:
{x-3y=5 ||*-3
{y+3x=-5

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

10x=-30 ||:10
x=-3

{x-3y=5
{y+3x=-5 ||*3

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

10x=10 ||:10
x=1
2010-01-05T18:54:41+01:00
Te kalmerki co sa dwie to powinna byc jedna i duza
A:
{x+y=2
{x-y=0

{x=-y+2
{-y+2-y=0

{x=-y+2
{-2y=-2 /(-2)

{x=-y+2
{y=1

{x=-1+2
{y=1

{x=1
{y=1
B:
{-x+y=5
{x+y=5

{y=5+x
{x+5+x=5

{y=5+x
{2x=5-5

{y=5+x
{2x=0 /2

{y=5+x
{x=0

{y=5+0
{x=0

{x=0
{y=5

C:
{5x+3y=0
{-x-2y=7

{5x+3y=0
{-x=7+2y //*(-1)

{5x+3y=0
{x=-7-2y

{5(-7-2y)+3y=0
{x=-7-2y

{-35-10y+3y=0
{x=-7-2y

{-7y=-35/(-7)
{x=-7-2y

{y=5
{x=-7-2*5

{x=-7-10
{y=5

{x=-17
{y=5
D:
{3s+5t=-6
{1,5s-2t=-3

{3s+5t=-6
{-2t=-3-1,5s /(-2)

{3s+5t=-6
{t=1,5+0,75s

{3s+5(1,5+0,75s)=-6
{t=1,5+0,75s

{3s+7,5+3,75s=-6
{t=1,5+0,75s

{6,75s=-13,5 /6,75
{t=1,5+0,75s

{s=-2
{t=1,5 + 0,75*(-2)

{s=-2
{t=1,5-1,5

{s=-2
{t=0

E:
{x-3y=5
{y+3x=-5

{x=5-3y
{y+3(5-3y)=-5

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

{x=5-3y
{-8y=-20 /(-8)

{x=5-3y
{y=2,5

{x=5-3*2,5
{y=2,5

{x=5-7,5
{y=2,5

{x=-2,5
{y=2,5