Question

решите систему уравнений 2х-у=-5 2х+3у=7

Answer 1

2х-у=-5

2х+3у=7

 

-2x+y=5

2x+3y=7

---------

4y=12

y=3

 

2x-3=-5

2x=-2

x=-1

Answer 2

{2х-у=-5/(-1)    {-2x+y=5

{2х+3у=7          {2x+3y=7

                         4y=12

                         y=12/4

                         y=3

2x+3*3=7

2x+9=7

2x=-2

x=-1

ответ:x=-1   y=3