Question

{2x-y=3 |*1 x+y=3 |*(-2)

Answer 1

{2x-y=3,  -2x-2y=-6;


2x-y=3 
+
-2x-2y=-6
---------------
-3y=3
y=3:(-3)
y=-1


{y=-1,  x+y=3;

{y=-1,  x-1=3;

{y=-1,  x=3+1;

{y=-1,  x=4.

Ответ: ( 4;-1)