[2(x y)³(y-x)]³÷[4(x y)²(x-y)]²-搜答案-智慧作业帮

等于1/X*（X-Y）

[(x+y)²-(x-y)二次方]÷2xy=(x²+2xy+y²-x²+2xy-y²)÷2xy=4xy÷2xy=2

对.前提是x不等于y

(x²-4y²)/(x²+2xy+y²)÷(x+2y)/(2x²+2xy)=(x-2y)(x+2y)/(x+y)²÷(x+2y)/(2x&s

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

2.题b的4次方/（a-b）3题x²+1/x²=（x+1/x)²-2=3²-2=74题t-v1t/(v1+v2)=v2t/(v1+v2)5题120/x-120/

【x²+xy/（x-y）】/【xy/（x-y）】=【x²（x-y）/（x-y）+xy/（x-y）】/【xy/（x-y）】={【x²（x-y）+xy】/（x-y）}/【xy

（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)

x²+y²+2xy分之x²-4y²÷x²+xy分之2y+x=(x+2y)(x-2y)/(x+y)²×x(x+y)/(x+2y)=x(x-2y

（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y=（x+y)（x-y)-y^2+（x-y)^2-2y（3x^2-xy)÷2y=（x+y)（x-y)-y^2+（x-y)^2

这个,最后面那个减号前面是怎么回事?打括号没有?这个很重要!再问：x-y/x²是一个整体分数，3个分数，啊！！！再答：把前面分子分母同城xy然后两个合并就可以了啊！

此题用的是完全平方公式（x+y)^2=x^2+2xy+y^2(x-y)^2=x^2-2xy+y^2所以（x+y)^2-(x-y)^2=4xy所以原式等于4xy/2xy=2

(3x^3y-x^2y+1/2xy)÷(-1/2xy）=[x^2y(3x-1)+1/2xy]*(-2xy)=-2x^3y^2(3x-1)-1=2x^3y^2-6x^4y^2-1

原式=(x+y)²/y(x-y)*(x-y)²/y(x+y)=(x+y)(x-y)/y²=(x²-y²)/y²

[(x-y)/(x+3y)]/[(x^2-y^2)/(x^2+6xy+9y^2)]-xy/(x+y)=(x-y)/(x+3y)*(x+3y)^2/(x-y)(x+y)-xy/(x+y)=(x+3y)/

原式=(x^2-y^2-x^2-2xy-y^2-2xy+2y^2-2xy)/xy=(-6xy)/xy=-6

(x-y)/x²÷(x²-2xy+y²)/xy×(xy-x²)=(x-y)/x²÷(x+y)²/xy×x(y-x)=(x-y)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^(-