x³ y³=

x-y/x-x+y/y-(x+y)(x-y)/y²y/x=2x-y/x-x+y/y-(x+y)(x-y)/y²y/x=2x-y/x-x+y/y-(x+y)(x-y)/y²

化简x/y(x+y)-y/x(x+y)=化简x/y(x+y)-y/x(x+y)=化简x/y(x+y)-y/x(x+y)=x^2-y^2为分子,xy(x+y)为分母

x(x+y)(x-y)-y(y+x)(y-x)=(x-y)()填空x(x+y)(x-y)-y(y+x)(y-x)=(x-y)()填空x(x+y)(x-y)-y(y+x)(y-x)=(x-y)()填空x

x+x+y+y+y=21,x+x+y+y+y+y+y=27,x,y=?x+x+y+y+y=21,x+x+y+y+y+y+y=27,x,y=?x+x+y+y+y=21,x+x+y+y+y+y+y=27,

x+x+y+y+y=21,x+x+y+y+y+y+y=27,x,y=?x+x+y+y+y=21,x+x+y+y+y+y+y=27,x,y=?x+x+y+y+y=21,x+x+y+y+y+y+y=27,

y=x(xy=x(xy=x(x在0点的左极限是0右极限是1左右极限不相等函数不连续因此不可导y(0-)=0y(0)=y(0+)=1因为在x=0处不连续，所以不可导。

x+x+x+x+y+y+y=56x+x+x+x+y+y+y=56x+x+x+x+y+y+y=564x+3y=56

x+x+x+y+y=6.4y+y+y+x+x=7.1怎么算?x+x+x+y+y=6.4y+y+y+x+x=7.1怎么算?x+x+x+y+y=6.4y+y+y+x+x=7.1怎么算?x+x+x+y+y=

二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)假设：X=Y/XY=

x-y/x+y=(x-y)²/x²-y²（x≠y)x-y/x+y=(x-y)²/x²-y²（x≠y)x-y/x+y=(x-y)²/

（x+y-5)*（x+y-5)+（x-y+3)=0x*x-y*y（x+y-5)*（x+y-5)+（x-y+3)=0x*x-y*y（x+y-5)*（x+y-5)+（x-y+3)=0x*x-y*y这是什么

已知:3x-5y=0,求x/y,x-y/y,x-y/x已知:3x-5y=0,求x/y,x-y/y,x-y/x已知:3x-5y=0,求x/y,x-y/y,x-y/x3x-5y=03x=5y→x/y=5/

推倒公式:(x+y)(x*x-3x+y*y)=x*x*x+y*y*y怎么做.推倒公式:(x+y)(x*x-3x+y*y)=x*x*x+y*y*y怎么做.推倒公式:(x+y)(x*x-3x+y*y)=x

D：y>=x,yD：y>=x,yD：y>=x,y

y''/y=1/xy''/y=1/xy''/y=1/xdy/dx=y/xdy/y=dx/x同时积分ln|y|=ln|x|+ce为底同时幂次方|y|=|x|+c这就是通解

x+y=5;x^y+y^x=17x+y=5;x^y+y^x=17x+y=5;x^y+y^x=17X=2,Y=3或X=3,Y=2x=3y=2或x=2y=3X=2Y=3X=2Y=3是容易得到的这个问题的难

X+Y=40,(X*Y)/(X+Y)=7.5X+Y=40,(X*Y)/(X+Y)=7.5X+Y=40,(X*Y)/(X+Y)=7.5（x*y）*40=7.5x*y=300因为y=40-x所以x*y=3

因式分解下列式子：x(x-y)+y(y-x)=?因式分解下列式子：x(x-y)+y(y-x)=?因式分解下列式子：x(x-y)+y(y-x)=?x(x-y)+y(y-x)=x(x-y)-y(x-y)=

x+y+|x-y|=-56求x*y最小值x+y+|x-y|=-56求x*y最小值x+y+|x-y|=-56求x*y最小值若x-y≥0,即x≥y,等式化为x+y+x-y=-56,解得x=-28,于是y≤

（x-y)2•(y-x)³(x-y)=?（x-y)2•(y-x)³(x-y)=?（x-y)2•(y-x)³(x-y)=?答：（x-y)