若x y 1,則x4 5x3y x2y 8x2y2 xy2 5xy3 y4的值等於

2021-04-18 17:21:42 字數 2913 閱讀 6104

1樓:匿名使用者

原式zhi=x4+x3y+4x3y+x2y+4x2y2+4x2y2+xy2+4xy3+xy3+y4,

dao=x3(

回x+y)+4x2y(x+y)+xy(x+y)+4xy2(x+y)+y3(x+y),

=-x3-4x2y-xy-4xy2-y3,=-[(x3+y3)+4xy(x+y)+xy],=-[(x+y)(

答x2-xy+y2)-4xy+xy],

=-[-(x2-xy+y2)-3xy],

=(x2-xy+y2)+3xy,

=(x+y)2-3xy+3xy,=1.

2樓:英文

這個值是不是有點廣泛

若x+y=-1,則x4+5x3y+x2y+8x2y2+xy2+5xy3+y4的值等於______

3樓:手機使用者

∵x+y=-1,

∴x4+5x3y+x2y+8x2y2+xy2+5xy3+y4,=(x4+2x2y2+y4

)+5xy(x2+y2)+xy(x+y)+6x2y2,=(x2+y2)2+5xy[(x+y)2-2xy]+xy(x+y)+6x2y2,

=[(x+y)2-2xy]2+5xy(1-2xy)-xy+6x2y2,

=(1-2xy)2+5xy-10x2y2-xy+6x2y2,=1-4xy+4x2y2+5xy-10x2y2-xy+6x2y2,=1+(-4xy+5xy-xy)+(4x2y2-10x2y2+6x2y2),

=1.故答案為:1.

.若x+y=-1,則x4+5x3y+x2y+8x2y2+xy2+5xy3+y4的值等於

4樓:匿名使用者

首先將x4+5x3y+x2y+8x2y2+xy2+5xy3+y4式子拆分項、運用完全平方式逐步整理分解,在整理過程中對於出現的專x+y用-1直接代屬入計算即可.

∵x+y=-1,

∴x4+5x3y+x2y+8x2y2+xy2+5xy3+y4,

=(x4+2x2y2+y4)+5xy(x2+y2)+xy(x+y)+6x2y2,

=(x2+y2)2+5xy[(x+y)2-2xy]+xy(x+y)+6x2y2,

=[(x+y)2-2xy]2+5xy(1-2xy)-xy+6x2y2,

=(1-2xy)2+5xy-10x2y2-xy+6x2y2,

=1-4xy+4x2y2+5xy-10x2y2-xy+6x2y2,

=1+(-4xy+5xy-xy)+(4x2y2-10x2y2+6x2y2),=1.

5樓:匿名使用者

若來x=-1 y=0 f=1若x=y=-1/2 f=1/16+5/16-1/8+8/16-1/8+5/16+1/16=1 故結果自

應該bai是du1(x+y)4=1=x4+4x3y+6x2y2+4xy3+y4f=1+x3y+x2y+2x2y2+xy2+xy3=1+xy(x2+x+2xy+y+y2)=1+xy((x+y)2+x+y)=1+xy(1-1)=1證明

zhi完畢dao

6樓:匿名使用者

原式=[(x+y)2-2xy]2+5xy[(x+y)2-2xy]+xy(x+y)+6x2y2=4x2y2-4xy+1+5xy-10x2y2-xy+6x2y2=1

若x+y=-1,則x4+5x3y+x2y+8x2y2+xy2+5xy3+y4的值等於(  )a.0b.-1c.1d.

7樓:匿名使用者

原式=x4+x3y+4x3y+x2y+4x2y2+4x2y2+xy2+4xy3+xy3+y4

,=x3(zhix+y)+4x2y(x+y)+xy(x+y)+4xy2(x+y)+y3(x+y),

=-x3-4x2y-xy-4xy2-y3,=-[(x3+y3)+4xy(x+y)+xy],=-[(x+y)(x2-xy+y2)-4xy+xy],=-[-(x2-xy+y2)-3xy],

=(x2-xy+y2)+3xy,

=(x+y)2-3xy+3xy,

=1.故選daoc.

若x+y=-1,則x的四次方+5x的三次方y+x的平方y+8x的平方y的平方+5xy的三次方+y的四次方的值為

8樓:小美妞和小屁孩

∵baix+y=-1,

du∴x4+5x3y+x2y+8x2y2+xy2+5xy3+y4,zhi

=(x4+2x2y2+y4)dao+5xy(x2+y2)+xy(x+y)+6x2y2,

=(x2+y2)2+5xy[(x+y)2-2xy]+xy(x+y)+6x2y2,

=[(x+y)2-2xy]2+5xy(1-2xy)-xy+6x2y2,

=(1-2xy)2+5xy-10x2y2-xy+6x2y2,

=1-4xy+4x2y2+5xy-10x2y2-xy+6x2y2,

=1+(-4xy+5xy-xy)+(4x2y2-10x2y2+6x2y2),內

=1.故答容案為:1.

若x+y=-1,則x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4

9樓:匿名使用者

^^^^

^^=(x^bai4+x^du3y)+(y^zhi4+xy^dao3)+(4x^專3y+4x^屬2y^2)+(4xy^3+4x^2y^2)+x^2y+xy^2

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

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

=-x^2(x+y)-y^2(x+y)-2xy(x+y)=x^2+y^2+2xy

=(x+y)^2=1

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