y=x的三次方-3x-1的极大值-搜答案-拍题作业网

1、(x+y)乘(x-y)的三次方+(x+y)的三次方乘(y-x)=（x+y)(x-y)((x-y)²-(x+y)²)=（x+y)(x-y)(x-y+x+y)(x-y-x-y)=-

已知x=4/5,y=-1/5,求x三次方-y的三次方+3x平方y-3xy的平方x三次方-y的三次方+3x平方y-3xy的平方=(x-y)³=[4/5-(-1/5)]³=(4/5+1

4x的三次方(-y的三次方)的平方-3x(—x)的平方(-y的平方)的三次方,x=-1,y=-2,=4x^3(-y^3)^2-3x(—x)^2(-y^2)^3=4x^3*(y^6)-3x*x^2(-y

x³y+2x²y²+xy³=xy(x²+2xy+y²)=xy(x+y)²=1×3²=9

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

（x+y）三次方×（2x+2y）三次方×（3x+3y）三次方=(x+y)³×8(x+y)³×27(x+y)³=216((x+y)的9次方

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

x³+y³=（x+y）（x²-xy+y²）=x²-xy+y²=（x+y）²-3xy=1-3xy=1/3∴xy=2/9x五次方+y五

(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=

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

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

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-

x+y=1,平方,x^2+2xy+y^2=1,又x^2+y^2=3,所以xy=-2x^3+y^3=(x+y)(x^2-xy+y^2)=1*(3+2)=5

绝对值平方大于等于0所以此题只有0+0=0满足题意|x+2|=0；(y+1)²=0解得x=-2;y=-1-3(x-2y)³-2(2x-y)³=-3(0)³-2(

原式=(x+y)³×[2(x+y)]³×[3(x+y)]³=(1/2)³×1³×(3/2)³=1/8×27/8=27/64

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)&

x三次方-3x²y+3xy²+4x²y-xy²+y的三次方=x三次方+2xy²+x²y+y的三次方当x=-1,y=-3时原式=-1-18-3

x^3-3x和y^3-3y都可以看成g(x)=x^3-3x对g(x)分析一下x=-1时极大值2x=1时极小值-2所以f(x,y)x=y=1时取极小值-3x=y=-1时取极大值5