x三次方 y三次方 z三次方=2017

X³+Y³=(X+Y)(X²-XY+Y²)

（x+1）的二次方+（y-1）+z的绝对值=0所以x+1=0,y-1=0,z=0所以x=-1,y=1,z=0所以A=-2-0=-2B=1-0+0=1C=1+2-0=3原式=A-2B+C-3A=-2A-

(x+y+z)^3-x^3-y^3-z^3=(x+y+z)^3-x^3-(y^3+z^3)=(x+y+z-x)[(x+y+z)^2+x(x+y+z)+x^2]-(y+z)(y^2-yz+z^2)=(y

令x+y=a,x+z=b,x+w=c,则a+b+c=2x.@又x^3+y^3+z^3+w^3=(a-x)^3+(b-x)^3+(c-x)^3+x^3=0带入@则(a-b-c)^3+(b-a-c)^3+

(x+y)^3+(z-x)^3-(y+z)^3=[(x+y)^3-(y+z)^3]+(z-x)^3=[(x+y)-(y+z)][(x+y)^2+(x+y)(y+z)+(y+z)^2]+(z-x)^3=

X的三次方+Y的三次方+Z的三次方=（x+y）（x2-xy+y2）+Z的三次方=-z（x2-xy+y2）+Z的三次方（x+y=-z）=-z（x2-xy+y2-z2）=-z[x（x-y）+(y+z)(y

x^3+y^3+z^3-3xyz=(x+y+z)(x^2+y^2+z^2-xy-yz-zx)=(x+y+z)[(x-y)^2+(y-z)^2+(z-x)^2]/2≥0x^3+y^3+z^3≥3xyz

=xy(4x²+4xy+y²)=xy(2x+y)²

1.为了简化算式,设A=2000的立方根,B=2001的立方根,C=2002的立方根A^3=2000,B^3=2001,C^3=2002A^3x^3=B^3y^3=C^z^3y=Ax/Bz=Ax/C2

x的三次方+8y三次方=(x+2y)(x平方-2xy+4y平方）

x³y-xy³=xy(x²-y²)=xy(x+y)(x-y)

a^3+b^3=(a+b)*(a^2-ab+b^2）.(a,b分别用X,Y代替吧,这是一个立方和公式)不过我感觉应该是最简了吧,如果用立方和来解开的话,计算步骤有会增多

/>x^3+y^3+z^3-3xyz=x^3+x^2y+x^2z+y^2x+y^3+y^2z+z^2x+z^2y+z^3-x^2y-y^2x-xyz-xyz-y^2z-yz^2-x^2z-xyz-z^

设2009x的三次方=2010y的三次方=2011z的三次方=k^3,则1995x^2=k^3/x,1996y^2=k^3/y,1997z^2=k^3/z【2009x的平方+2010y的二次方+201

z=x^3+y^3+3xy∂z/∂x=3x^2+3y∂^2z/∂x^2=6x=A∂z/∂y=3y^2+3x∂^2z/

=(x^2)(y^2)(7y-8xz)/(8x^2*y^2)=7y/8-xz

您好：x的三次方(y-x)的三次方-(x-y)的三次方=x的三次方(y-x)的三次方+(y-x)的三次方=（x³+1）(y-x)³=（x+1）（x²-x+1）(y-x)&

设2000x3=2001y3=2002z3=k则2000x2=k/x2001y2=k/y2002z2=k/z2000的立方根=k的立方根/x2001的立方根=k的立方根/y2002的立方根=k的立方根

2000X的三次方=2001Y的三次方=2002Z的三次方得出2000x=2001y=2002z三次根号下2000X的平方=三次根号下2000+三次根号下2001+三次根号下20022000x=根号（

设A=三次根号K,则A=X·三次根号2007=Y·三次根号2008=Z·三次根号2009A／X＝三次根号2007,A／Y＝三次根号2008,A／Z＝三次根号2009.A／X＋A／Y＋A／Z＝三次根号2