设 x^2y^2--20xy+x^2+y^2+81=0 ,求 x+y 的值.
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/09 22:57:35
xJ@_e@?)s*H](RȺ.Pt],MLWy.\|g9#Ҥ]4
B_W+ }v,LrbwuV/MĿޑGY|Nv@8C7=I0[{g{3+7Odz4[YI8e_2$|'Dmu]CUSn0⯟`ؕ.L]k]G
vz]B"$\)_K =-Qu6S D[
设f(x+y,x-y)=x^2+xy,求f(x,y)
因式分解(x+y-2xy)(x+y-2)+(xy-1)^2设x+y=a,xy=b,
设f(x+y,xy)=x^2+y^2-xy,则(∂f(x,y))/∂y=
设x,y∈R,比较(x*2+y*2)*2与xy(x+y)*2
设f(x+y,xy)=x^2+y^2,则f(x,y)
设x,y∈R,比较x^2+y^2+1与x+y+xy
设x、y∈R+,x+y+xy=2,则x+y的最小值为
设 x^2y^2--20xy+x^2+y^2+81=0 ,求 x+y 的值.
(-x-y)(x^2+xy+y^2)
化简x^-y^/x^-2xy+y^
2*(x-y)²(y-x)(xy)
设函数f(x,y)=xy/根号x^2+y^2,求limf(x,y)x,y趋于0
设F(xy,y^2/x)=x^2+y^2,求F(y^2/x,xy)
(x^2+xy/x-y)/(xy/x-y)计算
设函数f(xy,x+y)=x^2+y^2+xy,求∂f(x,y)/∂x和∂f(x,y)/∂y
设x>8,且xy=x+8y,求x+2y的最小值
设根号20的整数部分是x,小数部分为y,求xy/(x+y)+2/y值
设z=(x+2y)e^xy,求dz