Question

Решите систему х+2у=9 и -2х+3у=-11

Answer 1

x+2y=9          /.2
-2x+3y=-11    /.1
.........................
2x+4y=18
-2x+3y=-11      +
.........................
7y=7, y=1
x=9-2y,x=9-2.1=9-2,x=7
/x,y/=/7,1/