问题
解答题
已知x2-y2=xy,且xy≠0,求代数式x2y-2+x-2y2的值.
答案
∵x2-y2=xy,
∴原式=
+x2 y2
=y2 x2 x4+y4 x2y2
=(x2-y2)2+2x2y2 x2y2
=3x2y2 x2y2
=3.
已知x2-y2=xy,且xy≠0,求代数式x2y-2+x-2y2的值.
∵x2-y2=xy,
∴原式=
+x2 y2
=y2 x2 x4+y4 x2y2
=(x2-y2)2+2x2y2 x2y2
=3x2y2 x2y2
=3.