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DK: X.Y khac 0
{1+xy=6xy2x+yx2+y2(xy)2.(1+xy)=8⇔{1+xy=6xy2x+y(1)x2+y2(xy)2.(6xy2x+y)2=8(2)
giai 2 :(2)⇔0,5x2+3,5y2−4xy=0 (3)
ta thay y=o khong thoa man pt .do do ta chia ca 2 ve cho y2⇒ pt 3 tro thanh pt bac 2 an xy giai ra ta dc:
TH1 :xy=7
TH2: xy=1
(den day tu giai nha em.thay vao pt 1 la OK)
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