(x y )的三次方减(x-y)的平方乘(x y)-搜答案-拍题作业网

x^3-2x^2y^2+xy^3=x(x^2+2xy^2+y^3)很高兴为您解答,【学习宝典】团队为您答题.请点击下面的【选为满意回答】按钮,

x^3y-2x^2y^2+xy^3=x^3y+2x^2y^2+xy^3-4x^2y^2=xy(x^2+2xy+y^2)-4x^2y^2=xy(x+y)^2-4x^2y^2=12×7×7-4×12×12

x⁴-2y⁴-2x³y+xy³=(x+y)(x-2y)(x²-xy+y²)

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

原式=(x^4+xy³)-(2y^4+2x³y)=x(x³+y³)-2y(x³+y³)=(x-2y)(x³+y³)=(x

xy的三次方-2x²y²+x的三次方y=xy(y²-2xy+x²)=xy(x-y)²

先分解因式,后乘法.(X^4-Y^4)/(X^3+X^2Y+XY^2+Y^3)=(X-Y)(X+Y)(X^2+Y^2)/(X^3+X^2Y+XY^2+Y^3)=(X-Y)(X^3+X^2Y+XY^2+

(2x^4)y³－x³y^4=(x³y³)(2x－y)=(xy)³(2x－y)=4³×(1/16)=4

再问：谢谢大神再答：有问题继续密我

x²y³-2x(4xy³)=x²y³-2x²y³=-x²y³

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

4x的三次方y+4x²y²+xy的三次方=xy（4x²+4xy+y²）=xy（2x+y）²

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)

xy(x+y)²-4x³y³=xy[(x+y)²-4x²y²]=xy(x+y+2xy)(x+y-2xy)

x³y³－2x²y²＋xy＝xy（x²y²－2xy＋1）＝xy（xy－1）²

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

x³-y³-x²y+xy²=(x³-y³)-(x²y-xy²)=(x-y)(x²+xy+y²)-xy

x^3+y^3=271)x^2-xy+y^2=92)两式相除,得：x+y=3,平方得：x^2+2xy+y^2=93)2)*2+3)得：3(x^2+y^2)=27得：x^2+y^2=9