x三次方-y三次方 3xy²-3x²y-搜答案-灵鹊做题网

原式化简：(2x^3-3x^2y-2xy^2)-(x^3-2xy^2+y^3)+(-x^3+3x^2y-y^3)=2x^3-3x^2y-2xy^2-x^3+2xy^2-y^3-x^3+3x^2y-y^

3x³-5x²y+xy²+y³=3x³-3x²y-2x²y+2xy²-xy²+y³=3x²

已知x+y=1,则x^3+y^3+3xy=（x+y）(x^2-xy+y^2)+3xy=1×(x^2-xy+y^2)+3xy=x^2-xy+y^2+3xy=x^2+2xy+y^2=(x+y)^2=1^2

-6x²y-3x³-3xy²=-3x(2xy+x²+y²)=-3x(x+y)²

(5x的三次方+2x的四次方y-3xy的二次方)+(x的三次方+3xy的二次方+y的三次方)-（6x的三次方-x的二次方y的二次方+2y的二次方）=2x的四次方y-x的二次方y的二次方+2y的二次方+

X+Y=1X³+Y³+3XY=(X+Y)(X²-XY+Y²)+3XY=X²-XY+Y²+3XY=X²+2XY+Y²=(X

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

上式化简的最终结果是-2y的平方,也就是与x无关,所以无论x取几,答案都一样为2

首先x3-y3=(x-y)(x2+xy+y2)其次x3-y3-3xy=1所以x3-y3=1+3xy=(x-y)(x2+xy+y2)x-y=(1+3xy)/(x2+xy+y2)=(1+3xy)/[(x-

=xy(4x²+4xy+y²)=xy(2x+y)²

由题可知,x+y+1=0,xy+3=0即得x+y=-1,xy=-3（x+y)²=x²+2xy+y²∴(-1)²=x²+2×（-3）+y²即x

解x-y=5两边平方x²-2xy+y²=25∵xy=3∴x²+y²=25+2xy=25+6=31∴x³y+xy³=xy(x²+y&

x³y-xy³=xy(x²-y²)=xy(x+y)(x-y)

/>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^

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

(3xy)³+(xy)³=27x³y³+x³y³=28x³y³很高兴为您解答,【the1990】团队为您答题.请点击下面

x³－3x²y＋3xy²－y³＝﹙x³－y³﹚－3xy﹙x－y﹚＝﹙x－y﹚﹙x²＋xy＋y³﹚－3xy﹙x－y﹚＝﹙x

（x+y）^3-x^3-y^3+3xy=（x+y）^3-（x+y)(x²-xy+y²）+3xy=(x+y)(x²+2xy+y²-x²+xy-y

m=x^2-3xy^2+2xy^2+3y^3,n=x^3-2x^2+xy^2-5y^3,则2x-7x^2*y^3+5xy^+14y^3等于多少?3m=3x^2-9xy^2+6xy^2+9y^3n=x^