x,y为实数,且XX+YY/2+4≤XY+2Y求X,Y的值

x,y为实数,且XX+YY/2+4≤XY+2Y求X,Y的值 已知x,y是实数,且适合方程(xx+xy-12)(xx+xy-12)+(xy-2yy-1)(xy-2yy-1)=0求x,y的值 xx-2xy+yy+4x-4y+4 xx+4xy+yy-2x-4y+6 因式分解 因式分解：xx-2x-2yy+4y-xy 已知2x=3y,求xy/xx+yy-yy/xx-yy的值 x-y/x+y=2,则xx+2xy+yy/4xy=? 分解因式：x-y-xx+2xy-yy+2 长方形周长是16cm,两边x,y为整数,且满足x-y-xx+2xy-yy+2=0,求长方形的面积. 设集合A=｛x-y,x+y,xy},b={xx+yy,xx-yy,0},且A=B,求实数x与y的值及集合AB xx+2xy+yy-4x-4y-12的因式分解是多少 若x-y=4,求(xx+yy)÷2-xy的值 若x-y=4,求(xx+yy)÷2-xy的值 设x,y,z为不全为零的实数,求证 (2yz+2zx+xy)/(x^2+y^2+z^2)≤(√33+1)/4设x,y,z为不全为零的实数,求证(2yz+2zx+xy)/(x^2+y^2+z^2)≤(√33+1)/4 证明：只需考虑x≥0,y≥0,z≥0,2yz+2zx+xy≤1/2xx+1/2yy+γyy+(1/γ)zz+(1/γ)zz+γx 已知x(x-1)-(xx-y)=-3求xx+yy-2xy 已知x（x+1)-(xx+y)=3,求(xx+yy)/2-xy的值 x(x+1)-(xx+y)=-3,求(xx+yy)/2-xy的值 2xy-xx-yy