(-x+y)(y²+x²)再乘以( )就等于x`4-y`4 A.X-Y B.X+Y C.-X+Y D.-X-YA.X-Y B.X+Y C.-X+Y D.-X-Y`表示次方

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(-x+y)(y²+x²)再乘以( )就等于x`4-y`4 A.X-Y B.X+Y C.-X+Y D.-X-YA.X-Y B.X+Y C.-X+Y D.-X-Y`表示次方

(-x+y)(y²+x²)再乘以( )就等于x`4-y`4 A.X-Y B.X+Y C.-X+Y D.-X-YA.X-Y B.X+Y C.-X+Y D.-X-Y`表示次方
(-x+y)(y²+x²)再乘以( )就等于x`4-y`4 A.X-Y B.X+Y C.-X+Y D.-X-Y
A.X-Y B.X+Y C.-X+Y D.-X-Y
`表示次方

(-x+y)(y²+x²)再乘以( )就等于x`4-y`4 A.X-Y B.X+Y C.-X+Y D.-X-YA.X-Y B.X+Y C.-X+Y D.-X-Y`表示次方
就相当于用x^4-y^4除以(-x+y)(y^2+x^2)得到的结果,就是所求.
(x^4-y^4)/[(-x+y)(y^2+x^2)]
=[(x^2-y^2)(x^2+y^2)]/[(y-x)(y^2+x^2)]
=(x^2-y^2)/(y-x)
=(x+y)(x-y)/(y-x)
=-(x+y)(y-x)/(y-x)
=-(x+y)
——答案:D

x^4-y^4=(x^2+y^2)(x^2-y^2)=(y^2+x^2)( (-x)^2-y^2 )=(y^2+x^2)(-x+y)(-x-y)
对于选择题 也可以有简便方法
x=0时 (-x+y)(y²+x²)=y^3 x^4-y^4=-y^4 因此结果与 -y^4/y^3=-y相同 排除了BC
y=0时 (-x+y)(y²+x...

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x^4-y^4=(x^2+y^2)(x^2-y^2)=(y^2+x^2)( (-x)^2-y^2 )=(y^2+x^2)(-x+y)(-x-y)
对于选择题 也可以有简便方法
x=0时 (-x+y)(y²+x²)=y^3 x^4-y^4=-y^4 因此结果与 -y^4/y^3=-y相同 排除了BC
y=0时 (-x+y)(y²+x²)=-x^3 x^4-y^4=x^4 因此结果与 x^4/(-x^3)=-x相同 排除了A
因此答案是D

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答:
(-x+y)(y²+x²)k
=x^4-y^4
=(x²-y²)(x²+y²)
=(x-y)(x+y)(x²+y²)
所以:k=-(x+y)
所以:选择D看不懂诶多次运用平方差公式分解x^4-y^4
x^4-y^4=(x-y)(x+y)(x²+y&...

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答:
(-x+y)(y²+x²)k
=x^4-y^4
=(x²-y²)(x²+y²)
=(x-y)(x+y)(x²+y²)
所以:k=-(x+y)
所以:选择D

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