24.若用列举法表示集合A={(x,y)∣2x+y=1x−y=2}A=\{{{({x,y})}\left\vert \begin{array}{l}{2x+y=1}\\ {x-y=2}\end{array}\right.}\}A={(x,y)2x+y=1x−y=2},则A=A=A=____.