(2xy-y²)÷4y等于-搜答案-大师作文网

（2X-3Y-2XY)-(X-4Y+XY)=2X-3Y-2XY-X+4Y-XY=X+Y-3XY因为x加y等于110,xy等于33所以原式等于：110-33*3=11

x+2y

因为x+y除以xy等于4,所以,x+y=4xy2x-5xy+2y=2(x+y)-5xy=2*4xy-5xy=3xyx+2xy+y=4xy+2xy=6xy所以,2x-5xy+2y除以x+2xy+y的值＝

x,y＞0,2=4x+3y≥(4√3)√(xy).===>xy≤1/12.等号仅当x=1/4,y=1/3时取得.∴（xy)max=1/12.

4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2=(4xy-x²-2xy-y²)/[xy(x+y)(x-y)]÷[(x-y)(x+2y

=xy(x-y)×[-xy/(x-y)]=-(xy)²=-x²y²

x分之1-y分之1=4(xy)分之(y-x)=4y-x=4xyx-y=-4xy(x-2xy-y)分之(2x+xy-2y)=[(x-y)-2xy]分之[2(x-y)+xy]=(-4xy-2xy)分之(-

1/X-1/Y=4Y-X=4XY(2X+XY-2Y)/(X-2XY-Y)=[2(X-Y)+XY]/[(X-Y)-2XY]=7/6

（xy-y^2)÷x-y/xy=y(x-y)×[xy/(x-y)]=xy²

[2x(x²y-xy²)+xy(xy-x²)]÷x²y=[2x²y(x-y)+x²y(y-x)]÷x²y=2(x-y)+(y-x)

xy^2-2xy+2y-4

xy(y-2)+2(y-2)下步不写了能看懂吧?

4x+2xy+y等于

题出错了吧

xy+1/xy+y/x+x/y=[(xy)^2+1+x^2+y^2]/(xy)=[(xy)^2-2xy+1+x^2-2xy+y^2+4xy]/(xy)=[(xy-1)^2+(x-y)^2+4xy]/(

3x²-xy+y²=101-xy+4y²=421-2得3x²-3y²=6x²-y²=2选B

由已知条件可得：x-y=-4xy,（也就是在等式两边乘xy后整理,即可）,代入所求的式子里分母为-4xy+7xy,即3xy；分子为-4xy-2xy,即-6xy,化简得-2

|x-y|=4,xy=-3(x+y)^2=(x-y)^2+4xy=14-12=2x+y=根2,-根2xy^2+x^2y=xy(x+y)=-3根2,3根2再问：(x+y)^2=(x-y)^2+4xy=1

∵x=2,y=3∴2(xy^2+3y^3-x^2y)-(-2x^2y+y^3+xy^2)-4y^3=2xy²+6y³-2x²y+2x²y-y³-xy&

3x²y²-[5xy²-(4xy²-3)+2x²y²]=x²y²-xy²-3

x^2y+4xy+4y

x^2y+4xy+4y=y(x²+4x+4)=y(x+2)²

[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-x)^29^-x*27^y=3^-2x*3^3y=3^(-2x+3y)=3^(-