y²分之2x乘x分之2y-搜答案-大师作文网

1.7x=3.5y2.1/1.6:x=1/4:12/3x=(1/1.6)*(12/3)/(1/4)=10再问：1.X分之3.5等于Y分之7，X,Y不等于0，则X乘什么等于Y乘什么？2，解比例。1，6分

原式=[(x+2y)/(x+y)][xy/(x+2y)]÷[(x+y)/xy]=[xy/(x+y)]×xy/(x+y)=x²y²/(x+y)²

5X/14=5Y/14=1X=Y=14/55X-2Y=3X=3*14/5=42/5

前者分子：x^2-y^2=(x+y)(x-y)那前面这项就可以化简约分啦后者分子：4x^2-4xy+y^2=(2x)^2-2*2xy+y^2=(2x-y)^2建议你理解一下x^2-2xy+y^=(x-

题有错吧,没负号吧

1/x+1/y=-1/21/x*1/y=1所以由韦达定理1/x,1/y是方程x²+x/2+1=0的根判别式小于0所以无解再问：x分之一加y分之一=1，x乘y分之1=负2分之求x、y,谢谢，感

后半句意思都没表达清楚求采纳

y=2x/3则xy=2x2/3y2=4x2/9所以原式=(2x2/3)/(x2+4x2/9)-(4x2/9)/(x2-4x2/9)=(2/3)/(1+4/9)-(4/9)/(1-4/9)=6/13+4

(3y分之2x²）²乘4x分之3y+2y²分之x²除以xy分之3=4x^4/9y^2*3y/4x+x^2/2y^2*xy/3=x^3/3y+x^3/(6y)=(

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

原式=[(x+2y)/(x+y)]×[xy/(x+2y)]÷[(x+y)/xy]=[(x+2y)/(x+y)]×[xy/(x+2y)]×[xy/(x+y)]=x²y²(x+2y)/

成反比.因为:X与Y的乘积是定值1/2Y随X的增大而减小,Y随X的减小而增大,

1.若x分之1-y分之1=2,则求x-xy-y分之3x+xy-3y=0的值.若x分之1-y分之1=2变形（y-x）/xy=2,(y-x)=2xy(3x+xy-3y)/(x-xy-y)=[3(x-y)+

原式=[(x+y)/(x-y)]^2*[2(x-y)/5(x+y)-[X/(x^2y^2)]/[x/(x+y)]=2/5-[x/(x^2y^2)]*[(X+y)/x]=2/5-(x^2y^2)/(x+

把4拆成3+1(x²-2√3x+3)+(y²+2y+1)=0(x-√3)²+(y+1)²=0平方大于等于0相加等于0,若有一个大于0,则另一个小于0,不成立.所

13y-4x

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

原式=4(x-y)²/2(x+y)(x-y)*(x+y)/xy(x-y)=2(x-y)/(x+y)*(x+y)/xy(x-y)=2/xy=2/(2*3)=1/3再问：先化简，再求值额。。。

是这样的形式吗?[x/（x+y）+2y/（x+y）]×[xy/（x+y）]÷（1/x+1/y）一:原式=（x+2y）/（x+y）×[xy/（x+2y）]÷[（x+y）/xy]=x²y&sup

(3y/2x)×(4x²/9y²)=2x/3y;如果本题有什么不明白可以追问,