Question

1) Uporządkuj układy równań i rozwiąż je :

a) x-2y+3=3x-3y+5

6x+5y+1=y-2x

( w klamerce to jest)

2)

a) 2(x-1) + (y+2) =4

3(x+1)-(y-3)=7

b) -2(x-3)-(4-y)=0

5(x+1) +3(2-y)=17

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

2(y-1)-(3-x)=-10

dam naj :) !!!

Answer 1

a)

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

6x+5y+1=y-2x

 

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

6x+5y-y-2x=-1

 

-x+y=2

4x+4y=-1

 

y=2+x

4x+4(2+x)=-1

 

y=2+x

4x+8+4x=-1

 

y=2+x

8x=-1-8

 

y=2+x

8x=-9/:8

 

y=2+x

x=-9/8

 

y=2+x

x=-1 1/8

 

y=2+(-1 1/8)

 

x=-1 1/8

y=7/8

b)

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

5(x+1) +3(2-y)=17

 

-2x+6-4+y=0

5x+5+6-3y=17

 

-2x+y=0-6+4

5x-3y=17-5-6

 

-2x+y=-2

5x-3y=6

 

y=-2+2x

5x-3*(-2+2x)=6

 

y=-2+2x

5x+6-6x=6

 

 

 y=-2+2x

5x-6x=6-6

 

y=-2+2x

-x=0

 

y=-2+2x

x=0

 

y=-2+2*0

x=0

 

y=-2

x=0

c)

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

2(y-1)-(3-x)=-10

 

4x+12-2y-2=0

2y-2-3+x=-10

 

4x-2y=0-12+2

2y+x=-10+2+3

 

4x-2y=-10

2y+x=-5

 

5x=-15 /:5

x=-3

 

4*(-3)-2y=-10

-12-2y=-10

-2y=-10+12

-2y=2 /:(-2)

y=-1

 

x=-3

y=-1