x-y SX 2Y与xy (x y)的平方-搜答案-搜搜考试网

x/(xy-y²)=x/[y(x-y)]y/(x²-xy)=y/[x(x-y)]∴公分母为：xy(x-y)通分后得x/(xy-y²)=x²/[xy(x-y)]y

1:已知多项式x^2+2axy-xy^2与多项式3xy-axy^2-y^3的和不含xy项所以2a=-3a=-3/2x^2+2axy-xy^2+3xy-axy^2-y^3=x^2-xy^2+1/2xy^

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

xy(xy+1)+(xy+3)-2(x+y+1/2)-(x+y-1)^2=xy(xy+1)+(xy+1)+2-2(x+y)-1-[(x+y)^2-2(x+y)+1]=(xy+1)^2+2-2(x+y)

当k=__3__时,x²-kxy与y²+3xy-5的和不含xy项3-k=0;所以k=3；手机提问的朋友在客户端右上角评价点【满意】即可.再问：谢谢你~

(4xy-3x^2-xy+x^2+y^2)-(3xy-2x^2+2y)=3xy-2x^2+y^2-3xy+2x^2-2y=y^2-2y因为化简后的式子不含x项,所以它的值与x无关.

=(xy-x的平方）除以(x的平方-2xy+y的平方\xy)乘以(x-y\x的平方)=-x（x-y）×xy/（x-y）2×（x-y）/x2=-y再问：嗯

3xy-[2xy-2(xy-2分之3xy)+xy]+3xy=6xy-[2xy-2xy+3xy+xy)=6xy-4xy=2xy=2×3×3分之1=2

设这个多项式是t,则：t-2x^2-3xy=x^2+xyt=3x^2+4xy则这个多项式是3x^2+4xy再问：A3x^2-2xyBx^2-4xyC-x^2+4xyD3x^2+2xy再答：那就选B，2

1.其和为（x²+xy²/2-y³）2.e的值是（-6）3.证明（见下面详细过程）1.∵x²+2axy-xy²与3xy-axy²-y

这个是原题要求的吧|x|/x+|y|/y+|xy|/xy（1）xy>0x,y都大于零或都小于零x,y都大于零时|x|/x+|y|/y+|xy|/xy=|x|/x+|y|/y+|xy|/xy=x/x+y

-24x的平方-12xy 28xy

解题思路：提取公因式进行分解.解题过程：解：

X^2+AXY-XY^2+3XY-AXY^2-y^3=X^2+(A+3)XY-(A+1)XY^2-y^3不含XY项,所以A+3=0A=-3所以和=X^2+2XY^2-y^3

x的平方-2xy/xy-2y的平方＝x(x-2y)/y(x-2y)=x/y

原式(-xy/3)²*[xy(2x-y)-2x(xy-y²)]=(x²y²/9)(2x²y-xy²-2x²y+2xy²)

x²+xy=99x(x+y)=9*11x(x+y)=9*(9+2)x=9,y=2

16524

3(x^2-xy)-xy+y^2=3(x^2-xy)-(xy-y^2)=3*5-(-3)=15+3=18

解2x³-3xy-y²+(x³+xy+y²)=(2x³+x³)+(xy-3xy)+(y²-y²)=3x³-2x