6x三次方y-3x²-4xy 7 5x² 8xy-6x三次方y-10 合并同类项-搜答案-智慧作业帮

5/12[-4/3(x-y)的三次方](x+y）的平方（-x-y）的三次方（y-x）的二次方＝(-5/9)×(x-y)³×(x+y)²×[-(x+y)³]×(x-y)&#

(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

原式=-3x²y-10x^3+3x^3+6x^3y+3x²y-6x^3y+7x^3=0很明显,代数式的值与x,y无关

6.联立a-b=30,b-c=25,两式相加,得a-c=55,a方-b方=1650可拆分成（a+c)(a-c)=1650,除以前面得出来的就是a+c=305.既然无意义,说明y-5为0,就是y为5,x

6(x-y)的三次方+12(x-y)的平方-3(y-x)的平方=6(x-y)³+12(x-y)²-3(x-y)²=6(x-y)³+9(x-y)²=3(

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

多项式+（-2）^3+4(x^2)y+5y^3=x^3-3(x^2)y+2y^3,即：多项式=x^3-3(x^2)y+2y^3-[（-2）^3+4(x^2)y+5y^3]=x^3-(x^2)y-3y^

3x的三次方-[x的三次方+（6x的平方-7x)]-2(x的三次方-3x的平方-4x)=3x³-x³-6x²+7x+2x³-6x²-8x=4x

3(x-2y)-x²y(2y-x)=3(x-2y)+x²y(x-2y)=(x-2y)(3+x²y)

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

7x^3-6x^3y+3x^2y+3x^3+6x^3y-3x^2y-10x^3,其中x=-2010.y=2012=(7x^3+3x^3-10x^3)+(6x^3y-6x^3y)+(3x^2y-3x^2

-3（1/2x³-1/3y³+1/6）+2（1/3x³-1/2y³+1/4）=-3/2x³+y³-1/2+2/3x³-y³

3x（x-y）三次方-6y（y-x）二次方=3x(x-y)³-6y(x-y)²=3(x-y)²(x²-xy-2y)

=xy(4x²+4xy+y²)=xy(2x+y)²

/>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^

2x³+3x³-4x³=(2+3-4)x³=x³

4y(y-x)的2次方-6y(x-y)三次方=4y(x－y)²－6y(x-y)³=2y(x－y)²(2－3x＋3y)【提取公因式2y(x－y)²】

18x的9次方

∵x²+y²+6x-2y+10=0∴(x²+6x+9)+(y²-2y+1)=0即(x+3)²+(y-1)²=0由平方的非负性可得(x+3)&

结果是3（x-y）的2次方与（2x-5y）的积3（x-y）的2次方乘以2（x-y）-3（x-y）乘以3y,提取3（x-y）的2次方得3（x-y）的2次方乘以（2x-2y-3y）,合并得：3（x-y）的