【因式分解】x-y=1 求x^3-y^3-3xy- - 知识问答

【因式分解】x-y=1 求x^3-y^3-3xy-5的值

3个回答

x^3 -y^3 -3xy-5
=(x-y)(x^2+y^2+xy)-3xy-5
=x^2+y^2+xy-3xy-5
=x^2+y^2-2xy-5
=(x-y)^2-5
=1-5
=-4

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