Question

vă rog măcar două ❤
îmi trebuiesc maine la ora 8:00
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Answer 1

Răspuns:

1)

x+y=1    | *(-1)

x+2y=-1

-x-y=-1

x+2y=-1

------------

y=-2

x+y=1

x-2=1

x=1+2

x=3

2)

4x-2y=10

2x+3y=1   | *(-2)

4x-2y=10

-4x-6y=-2

---------------

-8y=8

8y=-8

y=-1

2x+3y=1

2x-3=1

2x=1+3

2x=4

x=2

3)

4x-2y=-2

3x+y=-9  | *2

4x-2y=-2

6x+2y=-18

---------------

10x=-20

x=-2

3x+y=-9

-9+y=-9

y=-9+9

y=0

4)

x+2y=8

x-y=1     | *2

x+2y=8

2x-2y=2

--------------

3x=10

x=10/3

x+2y=8

10/3+2y=8

2y=8-10/3

2y=24/3-10/3

2y=14/3

y=7/3

5)

3x-2y=8  | *(-3)

x-6y=8

-9x+6y=-24

x-6y=8

-----------------

-8x=-16

8x=16

x=2

3x-2y=8

6-2y=8

-2y=8-6

-2y=2

2y=-2

y=-1