Question

решите систему уравнений

{2х-3у=8,

{х+у=9

 

{2х+у=12,

{х2-у=23

Answer 1

x=9-y

3y-2(9-y)=8

3y-18+2y=8

y=26

x=9-26=-17

 

y=12-2x

2x-(12-2x)=23

2x-12+2x=23

4x=11

x=11/4

y=12-11/2