设斜率是k
y-2=k(x-2)
y=0,x=-2/k+2=(2k-2)/k
x=0,y=2-2k
所以截距和=(2k-2)/k+(2-2k)=-1
2k-2+2k-2k²=-k
2k²-5k+2=0
k=2,k=1/2
所以2x-y-2=0和x-2y+2=0