y=x方 2x 3分之2x方 4x-7

若X方-2XY+Y方+1XY-11=0则：x-y=0.而且xy=1所以,x=y=1,或者,x=y=-1所以,x/y=1X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y=（x²

即y=3x/2z=2x代入原式=(5x²+9x²/2-4x²)/(2x²-27x²/4-4x²)=(11x²/2)/(-35x&#

因为3x方+xy-2y方=0,即（x+y)(3x-2y)=0,而x+y≠0,所以3x-2y=0原式=[（x+y)^2-4xy]/[(x+3y)(x-y)/(x+3y)(x-3y)=(x-3y)/(x+

-5/2≤y＜2y=[2(x^2+2x+3)-9]/(x^2+2x+3)=2-9/(x^2+2x+3)=2-9/[(x+1)^2+2]以后的就自己算了

很高兴喂你解答!原式=4√[(x^2+xy+y^2)/(x-y)*1/2√[(x^2-xy+y^2)/(x+y)*3√(x^3+y^3)=6√[(x^2+xy+y^2)/(x-y)*√[(x^2-xy

【俊狼猎英】团度为您解答~原式=[(x^2-y^2)*2(x-y)^2]/[xy(xy-y^2)]先约掉一个(x-y),分子分母同时处以y^3得到2[(y/x)^2-1]*[(y/x)-1]/[(y/

∵y/x=3∴y=3x∴原式=(3x²-12x²+18x²)/（6x²-3x*3x+7*9x²)=9x²/(60x²)=3/20

∵x^2+y^2-2x+4y+5=0配方：∴(x-1)^2+(y+2)^2=0那么x-1=0且y+2=0所以x=1,y=-2∴(x^4-y^4)/(2x^2+xy-y^2)*（2x-y)/(xy-y^

∵y分之x=5∴x=5y(4x²-5xy-6y²)分之(x²-2xy+3y²)=(100y²-25y²-6y²)分之(25y

x+y=x-(x+3/2)^2+21/4=x-x^2-9/4-3x+21/4=-x^2-2x+12/4=-(x+1)^2+4因为-(x+1)^2

8x^2-6y^2=146x^2+4y^2=3814x^2-2y^2=52

将x^2+y^2+5/4=2x+y化为将x^2-2x+1+y^2-y+1/4=0即(x-1)^2+(y-1/2)^2=0上面的等式成立,则有x-1=0且y-1/2=0即x=1,y=1/2所以xy/(x

因为y=log2（t）是增函数,若求该函数的减区间,则需求t=2x方-5x-3的减区间,即为（5/4,正无穷）,又因为有定义域的限制,所以求其交集即为x>3

y=2x^2+3/x^2根据基本不等式：a+b>=2根号ab那么2x^2+3/x^2>=2根号[2x^2×3/x^2]=2根号6所以最小值为2根号6新春快乐!

两边同除以x^2y'/(x^2)-(2/x^3)y=x通分(xy'-2y)/(x^3)=x[y/(x^2)]'=x积分y/(x^2)=(1/2)x^2+Cy=(1/2)x^4+Cx^2再问：请问，最终

(4x^2-y^2)/(-2x-y)=(2x+y)(2x-y)/-(2x+y)=-(2x-y)=y-2x

6已知x+y=2,x-y=1,求分式x方+2xy+y方分之x方-y方的值x方+2xy+y方分之x方-y方=(x+y)(x-y)/(x+y)²=(x-y)/(x+y)=1/27已知x分之1-y

已知x方-4x+4+|y+x|=0,===>(X-2)^2+ly+xl=0====>x=2,y=-2,代入求解即可.（平方数>=0,绝对值>=0)再问：我问一下你的======是什么意思？你能帮我把过

(3x分之y)的平方×(-y分之x)的三次方÷(-x分之2y)方=(y²/9x²)(-x³/y³)(x²/4y²)=-x³/36y

4x方-4xy+y方-4x+2y-15=(2x-y)^2-2(2x-y)-15=(2x-y-5)*(2x-y+3)4x方y方-5x方y方-9y方题目弄错了吧,应该是这样的吧=4x^2y^2-5xy-9