Question

rozwiąż metodą podstawiania

2x-y=5

x+y=4

-7x+y=4

2x+3y=12

3x-2y=10

x+4y=1

Answer 1

1.  2x-y=5

x+y=4

 

2x-y=5

y=4-x

 

2x-4+x=5

y=4-x

 

3x=9 I:3

y=4-x

 

x=3

y=1

 

 

2.  -7x+y=4

2x+3y=12

 

y=4+7x

2x+12+21x=12

 

y=4+7x

23x=0|:23

 

y=4

x=0

 

3. 3x-2y=10

x+4y=1

 

3x-2y=10

x=1-4y

 

3-12y-2y=10

x=1-4y

 

-14y=7I:(-14)

x=1-4y

 

y=0.5

x=1-2

 

y=0.5

x= -1

 

Answer 2

2x-y=5

x+y=4

2x-y=5

x=4-y

2*(4-y)-y=5

x=4-y

8-2y-y=5

x=4-y

8-3y=5

x=4-y

-3y=5-8

x=4-y

-y=-3

x=4-y

y=1

x=4-y

y=1

x=4-1

y=1

x=3

 

-7x+y=4

2x+3y=12

y=4+7x

2x+3*(4+7x)=12

y=4+7x

2x+12+21x=12

y=4+7x

23x+12=12

y=4+7x

23x=0

y=4+7x

x=0

y=4+7*0

x=0

y=4

 

3x-2y=10

x+4y=1

3x-2y=10

x=1-4-y

3*(1-4y)-2y=10

x=1-4-y

3-12y-2y=10

x=1-4-y

3-14y=10

x=1-4-y

-14y=7

x=1-4-y

y=-1/2

x=1-4*(-1/2)

y=-1/2

x=1+2

y=-1/2

x=3