2x3-3x2y+y3

(2x3-3x2y-2xy2)-(x3-2xy2+y3)+(-x3+3x2y-y3)当x=1/2,y=-1时,求值.当x=-1/2,y=-1时,求值.(2x3-3x2y-2xy2)-(x3-2xy2+y3)+(-x3+3x2y-y3)当x=

试说明代数式(x3+3x2y-4xy2+6y3)-(2x3-x2y-xy2-y3-1)+(x34x2y+3xy2-7y3)的值与xy取值无关试说明代数式(x3+3x2y-4xy2+6y3)-(2x3-x2y-xy2-y3-1)+(x34x2

设A=x3+3x2y-2xy2+4y3-1,B=y3-xy2+x2y-2x3,C=-x3+4x2y-3xy2+5y3+5.求证：不论x,y取任何有理数,多项式A+B-C的值总等于一个常数,并求出这个常数设A=x3+3x2y-2xy2+4y3

x3+2x2y+2xy2+y3因式分解x3+2x2y+2xy2+y3因式分解x3+2x2y+2xy2+y3因式分解x3+2x2y+2xy2+y3原式=x(x2+2xy+2y+y3)x^3+2x^2y+2xy^2+y^3=(x^3+y^3)+

A=x3-2y3+3x2y-3xy+4B=y3-x3-4x2y-3xy-3xy2+3C=y3+x2y+2xy2+6xy-6试说明对于xyz的任何值A+B+C是常数希望可以给我一个详细的答案,A=x3-2y3+3x2y-3xy+4B=y3-x

计算（2x3-3x2y-2xy2)-(x3-2xy2＋y3)＋(-x3＋3x2y-y3)的值,其中x=0.5,y=-1.小明同学在计算时错把x=0.5抄成了x=-0.5,但他计算的结果也是正确的,试说明理由,并求出这个结果计算（2x3-3x

若m=x3-3x2y+2xy2+3y2n=x3-2x2y+xy2-5y3,则2x3-7x2y+5xy2+14y2等于()若m=x3-3x2y+2xy2+3y2n=x3-2x2y+xy2-5y3,则2x3-7x2y+5xy2+14y2等于()

试说明:无论x,y取何值时,代数式(x3+3x2y-5+6y3)+(y3+2xy2+x2y-2x3)-(4x2y-x3-3xy2+7y2)的值是常数.要具体过程,注意格式试说明:无论x,y取何值时,代数式(x3+3x2y-5+6y3)+(y

因式分解：x3-y3-x2y+xy2因式分解：x3-y3-x2y+xy2因式分解：x3-y3-x2y+xy2x3-y3-x2y+xy2=(x-y)(x2+xy+y2)-xy(x-y)=(x-y)(x2+xy+y2-xy)=(x-y)(x2+

x3+x2y-xy2-y3=x3+x2y-xy2-y3=x3+x2y-xy2-y3=3x一3y

分解因式:X3+2X2Y+2XY2+Y3=分解因式:X3+2X2Y+2XY2+Y3=分解因式:X3+2X2Y+2XY2+Y3=解x³+2x²y+2xy²+y³=(x³+y³)+(2

试说明:无论x,y取何值时,代数式(x3+3x2y-5xy+6y3)+(y3+2xy2+x2y-2x3)-(4x2y-x3-3x试说明：无论x,y取何值时，代数式(x^3+3x^2y-5xy+6y^3)+(y^3+2xy^2+x^2y-2x

x.y取何值时,代数(x3y+3x2y-5xy2+6y3)+(y3+2xy2+x2y-2x3)-(4x2y-x3-3xy2+7y3).y取何值时，代数（x3y+3x2y-5xy2+6y3）+（y3+2xy2+x2y-2x3）-（4x2y-x

(4xy2-2x2y)-()=x3-2x2y+4xy2+y3．(4xy2-2x2y)-()=x3-2x2y+4xy2+y3．(4xy2-2x2y)-()=x3-2x2y+4xy2+y3．(4xy^2-2x^2y)-(-x^3-y^3)=x^

有这样一道题：“求（2x3－3x2y－2xy2）－（x3－2xy2＋y3）＋（－x3＋3x2y－y3）的值,其中x＝1/2,y＝－1.”小明把“x＝1/2”错抄成“x＝－1/2”,但他计算的结果也是正确的.试说明原因.有这样一道题：“求（2

有这样一道题：“求（2x3－3x2y－2xy2）－（x3－2xy2＋y3）＋（－x3＋3x2y－y3）的值,其中x＝1/2,y＝1甲同学把x＝1/2”错抄成“x＝－1/2”,但他计算的结果也是正确的.试说明原因有这样一道题：“求（2x3－3

分解因式x3+y3-x2y-xy2分解因式x3+y3-x2y-xy2分解因式x3+y3-x2y-xy2x^3+y^3-x^2*y-x*y^2=x^3-x^2*y+y^3-x*y^2=x^2(x-y)+y^2(y-x)=x^2(x-y)-y^

x3-y3-x2y+xy2分解因式x3-y3-x2y+xy2分解因式x3-y3-x2y+xy2分解因式x³-y³-x²y+xy²=(x³-x²y)+(xy²-y³

分解因式x3-xy2+x2y-y3分解因式x3-xy2+x2y-y3分解因式x3-xy2+x2y-y3x3-xy2+x2y-y3=x(x^2-y^2)+y(x^2-y^2)=(x^2-y^2)(x+y)=(x+y)^2(x-y)x3-xy2

已知A=x3－2y3＋3x2y＋xy2－3xy＋4,B=y3－x3－4x2y－3xy－3xy2＋3,C=y3＋x2y＋2xy2＋6xy－6,试着说明对于x,y,z的任何值,A＋B＋C是常数.某同学做一道代数题：求代数式10x9＋9x8＋8x