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$x^{3}-y^{3}=6xy+3$

nghiệm nguyên

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#1
hoangkimca2k2

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giải phương trình nghiệm nguyên $x^{3}-y^{3}=6xy+3$


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#2
Tea Coffee

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giải phương trình nghiệm nguyên $x^{3}-y^{3}=6xy+3$

Có: $x^{3}-y^{3}=6xy+3<=>(x-y)^{3}+3xy(x-y)=6xy+3$

$\left\{\begin{matrix}3xy=a \\ x-y=b \end{matrix}\right. (a,b\epsilon \mathbb{Z})$

$=>b^{3}+ab=2a+3<=>b^{3}-8+a(b-2)=-5<=>(b-2)(b^{2}+2b+4+a)=-5...$


Edited by Tea Coffee, 22-05-2018 - 00:06.

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