Question

rozwiąż uklad metoda podstawiania

0,4x+y=6

x+0,75y=8

nastepne

2x=1-3y

0,5x=2-y

kolejne

x-y-3=0

2x+3y-11=0

ostatnie

-3[x+2]+2[x+y]=2

2[y+2]+3[x-y]=2x-1

Answer 1

0,4x+y=6

x+0,75y=8

y = 6 - 0,4x

x + 0,75(6 - 0,4x) = 8

y = 6 - 0,4x

x + 4,5 - 0,3x = 8

y = 6 - 0,4x

0,7x = 3,5 /: 0,7

y = 6 - 0,4x

x = 5

y = 6 - 0,4 * 5

x = 5

y = 6 - 2 = 4

nastepne

2x=1-3y

0,5x=2-y

2x + 3y = 1

 y = -2 + 0,5x

2x + 3(-2 + 0,5x) = 1

y = -2 + 0,5x

2x - 6 + 1,5x = 1

y = -2 + 0,5x

3,5x = 7 /: 3,5

y = - 2 +0,5x

x = 2

y = -2 + 0,5 * 2

x = 2

y = -2 + 1 = -1

kolejne

x-y-3=0

2x+3y-11=0

x = 3 + y

2(3 + y) + 3y = 11

x = 3 + y

6 + 2y + 3y = 11

x = 3 + y

5 y = 5 /:5

x = 3 + y

y = 1

x = 3 + 1 = 4

y = 1

ostatnie

-3[x+2]+2[x+y]=2

2[y+2]+3[x-y]=2x-1

-3x - 6 + 2x + 2y = 2

2y + 4 + 3x - 3y = 2x - 1

-x + 2y = 8

-y + 3x - 2x = -1 -4

x = -8 + 2y

-y + x = -5

x = - 8 +2y

-y - 8 + 2y = -5

x = - 8 + 2y

y = 3

x = - 8 + 2*3

y = 3

x = - 8 + 6 = -2

y = 3

Answer 2

{0,4x+y=6

{x+0,75y=8|*(-0,4)

 

{o,4x+y=6

{-0,4x-0,3y=-3,2

    0,7y=2,8|:0,7

 

{y=4

{x+0,75*4=8

 

{y=4

{x=5

__________

{2x=1-3y

{0,5x=2-y

 

{2x+3y=1

{0,5x+y=2|*(-4)

 

{2x+3y=1

{-2x-4y=-8

    -1y=-7|:(-1)

{y=7

{2x+3*7=1

 

{y=7

{2x+21=1

 

{x=-10

{y=7

_______

{x-y-3=0

{2x+3y-11=0

 

{x-y=3|*3

{2x+3y=11

 

{3x-3y=9

{2x+3y=11

     5x=20|:5

{x=4

{4-y=3

 

{y=1

{x=4

_______

{-3(x+2)+2(x+y)=2

{2(y+2)+3(x-y)=2x-1

 

{-3x-6+2x+2y=2

{2y+4+3x-3y=2x-1

 

{-3x+2x+2y=6+2

{2y-3y+3x-2x=-4-1

 

{-1x+2y=8

{-1y+1x=-5

     1y=3|:3

{y=3

{-1x+2*3=8

 

{y=3

{x=(-2)

 

:)