[kanakon]

ข้อ 2 ผมคิดได้
$$(x,y)=(3,3),(-4,-4),(\frac{1+\sqrt{45} }{2},\frac{1-\sqrt{45} }{2}),(\frac{1-\sqrt{45} }{2},\frac{1+\sqrt{45} }{2})$$