若x^4+y^4=15,xy^2-x^2y=-5,求x^4-y^4+3xy^2-x^2y-2xy^2+2y^4_数学解答

若x^4+y^4=15,xy^2-x^2y=-5,求x^4-y^4+3xy^2-x^2y-2xy^2+2y^4

人气：290 ℃　时间：2019-10-11 11:35:30

解答

x^4-y^4+ 3xy^2-x^2y-2xy^2+2y^4
= (x^2)^2-(y^2)^2+xy(3y-x-2y)+2(y^2)^2
=(x^2)^2+(y^2)^2+xy(y-x)
=10