已知x y=2,求(x y)的三次方乘(2x 2y)的平方的值-搜答案-智慧作业帮

原式=2xy(x²+2xy+y²)=2xy(x+y)²=2*2*4²=64

A-B=x³+2y³-xy²-(-y³+x³+2xy²)=x³+2y³-xy²+y³-x³

x-xy=8(1)xy-y=-9(2)则有(1)-(2):X-XY-XY+Y=X+Y-2XY=8-(-9)=17

/>根据非负数之和为0得x+1=02(y-2）=0解得x=-1y=2于是x³-3xy+y³=-1³-3×(-1)×2+2³=-1+6+8=13

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

-xy（x^2y^5-xy^3-y)=-(xy^2)^3+(xy^2)^2+xy^2=-(-2)^3+4-2=8+4-2=10

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

已知A=x³+2y³-xy²,B=-y³+x³+2xy²,其中x等于1\3,y等于2A-B=（x³+2y³-xy

x²+xy+x=4y²+xy+y=2两式相加：x²+2xy+y²+x+y=4+2=6(x+y)²+(x+y)=6(x+y+1/2)²=25/

=xy(x²-2xy+y²)=xy(x-y)²=2*1²=2

x³y-2x²y+xy=xy(x²-2x+1)=xy(x-y)²=1/2×2²=2

xy的平方·(-x的平方y的平方)·(2分之1xy的三次方)的平方=(xy)^2*(-x^2y^2)*(xy)^6/4=-(xy)^10/4=-[(xy)^2]^5/4=-2^5/4=-8

∵x-y=-2,xy=-1/4∴-2x²y²+xy³+x³y=xy(x²-2xy+y²)=xy(x-y)²=-1/4*(-2)&#

原式=xy(x²-2xy+y²)这一步就很清楚的明白是公式的运用了：a²-2ab+b²=(a-b)²所以=xy(x-y)²将x-y=-1,x

原式=xy(x²-2xy+y²)=xy(x-y)²=2×1²=2

-xy(x²y的五次方-xy的三次方-y)=-x³y的6次方+x²y的4次方+xy²=-（xy²）³+（xy²）²+xy

我想你要求的是：x^3y+2x^2y^2+xy^3=xy(x+y)^2=-4,化简,代入即可

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&

x的三次方y-xy的三次方=xy(x²-y²)=xy(x+y)(x-y)=-3x0x(x-y)=0如果本题有什么不明白可以追问,如有其它问题,请谅解,