Question

Rozwiąż ukłądy równań dowolnym sposobem.

1) x+y=18

2x+y=26

2) x-y=8

x+2y=23

3) x+z=12

3x-z=8

4) -y+z=15

2y-z=3

5) -x-y=7

2x+3y=10

6) 3x-2y=13

2x-3y=8

7) 2x+5y=25

4x+3y=15

8) 4x+3y=-4

6x+5y=-15

9) 5(x-y)+3=2(x+y)-7

2-3(x+y)=4y-5x

10) 2y+z=y-2z=5

y-2z=z-2y-9

11) -3(-x+1)+2(-y+1)=8

1-3x-4(y+2)=0

12) 4x-3y=2x-3y+6

x+5y=2y-3x+6

13) \frac{x+y}{2} +1= \frac{x-y}{4}

x+y=2

14) \frac{2y-z}{4} -z=5- \frac{y+2z}{6}

\frac{y}{3} - \frac{z}{2} =1

15) \frac{2x-y}{2} - \frac{1}{2} = \frac{3y+2x}{3} +81

2x-y=11

16) (x-1)^{2} - (y-3)^{2} =(x+y)(x-y)

\frac{x+3}{5} - \frac{y+1}{3} =x-y

17) (x-1)^{2} - (y-5){2} = (x+y)(x-y){2}

\frac{x+1}{4} - \frac{y+1}{2} = x-4

18) (x+1){2} + y{2} -8= (y-2){2} + (x-3)(x+3)

3x-y+4=0

19) (x-1){2} - (y+2){2} = (x-y)(x+y)

x+y= \frac{1}{2}

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

2x-3y=2

Answer 1

1) x +y=18

2x+y=28

 

x = 18-y

2(18-y) + y=28

36-2y+y=28

36-y=28

-y=-8

y=8

 

x = 18-8

x=10

 

 

2)x-y=8

    x+2y=23

 

x=8+y

8+y + 2y=23

3y=15

y=5

x=8+y

x=8+5

x=13

 

 

3) x+z=12

    3x-z=8

x=12-z

3(12-z) - z=8

36-3z-z=8

-4z=-28

z=7

 

4) -y+z=15

    2y-z=3

 

z=15+y

2y-(15+y) = 3

2y-15-y=3

y=18

z=15+18

z=33

 

 

5) -x-y=7

    2x+3y=10

-x=7+y

x=-7-y

 

2(-7-y) +3y = 10

-14 - 2y + 3y=10

y=24

 

x=-7-y

x=-7-24

x-31

 

6) 3x-2y=13

    2x-3y=8

 

2x=8+3y

x=8+3y/2

x=4+1,5y

 

3(4+1,5y) - 2y=13

12+4,5y-2y=13

2,5y=1

y=0,4

x = 4+1,5*0,4

x=4+0,6

x=4,6

 

 

 

Jak dasz więcej punktów za to zadanie, to mogę robić dalej :)