Question

rozwiąż układy równań:

x+y=6

2x-3y=-8

3x-2y=15

x-y=6

5x+y=7

-3x-2y=-7

-x-y=-3

2x+4y=10

potrzebne jeszcze na dziś, daje naj !; DDD.

Z góry dzięki.

Answer 1

x+y=6

2x-3y=-8

 

x = 6-y

2(6-y) - 3y = -8

 

x= 6 - y

12 - 2y - 3y = -8

 

x = 6 - y

-5y = -8 - 12

 

x = 6-y

-5y = -20 /: (-5)

 

x= 6-y

y= 4

 

x= 6-4

y= 4

 

x = 2

y = 4

 

3x-2y=15

x-y=6 / * 2

 

3x - 2y = 15

2x - 2y = 12

 

3x - 2y + 2x - 2y = 15 + 12

5x = 27 /:5

x= 5,4

 

x - y = 6

y= 6 - 5,4

y= 0,6

 

5x+y=7 /*2

-3x-2y=-7

 

10x + 2y = 14

- 3x - 2y = 7

 

10x + 2y - 3x - 2y = 14 + 7

7x= 21 /:7

x= 3

 

10 x + 2y = 14

10 * 3 + 2y = 14

2y = 14 - 30

2y = -16 /:2

y= -8

 

 

-x-y=-3

2x+4y=10

 

-x = -3 + y /* (-1)

2x + 4y = 10

 

x= 3 - y

2(3 - y) + 4y = 10

 

x = 3 -y

6 - 2y + 4y = 10

 

x= 3 - y

2y = 4 /:2

 

x= 3 - y

y= 2

 

x= 3- 2

y= 2

 

x=  1

y=2

 

 

Dasz naj ? :)

Answer 2

x=6-y

2(6-y)-3y=-8

12-2y-3y=-8

12-5y=-8

-5y=-8-12

-5y=-20

y=4

 

x=6-4=2

 

2+4=6

2x2-3x4=-8

4-12=-8

 

3x-2y=15

x-y=6

x=6+y

3(6+y)-2y=15

18+3y-2y=15

y=15-18=-3

x=6-3=3

3x3-2x(-3)=15

9+6=15

3-(-3)=6

3+3=6

 

5x+y=7

-3x-2y=-7

y=7-5x

-3x-2(7-5x)=-7

-3x-14+10x=-7

7x=-7+14

7x=7

x=1

y=7-5x1=7-5=2

 

5x1+2=7

5+2=7

-3x1-2x2=-7

-3-4=-7

 

-x-y=-3

2x+4y=10

-x=-3+y

x=3-y

2(3-y)+4y=10

6-2y+4y=10

2y=10-6

2y=4

y=2

x=3-2=1

 

-1-2=-3

2x1+4x2=10

2+8=10