已知|x-2y-1|+x2+4xy+4y2=0,则x+y= ___ .
已知实数x,y满足x2+4xy+4y2-x-2y+14=0,则x+2y的值为 ___ .
已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以(x2+y2/x
已知x+y=4,xy=2,则x2+y2+3xy=______.
已知x2+y2-2x-4y+5=0,则1xy+1(x+1)(y+1)+1(x+2)(y+2)+…+1(x+2010)(y
已知正实数x,y满足x2+y2+xy=1,则x+y的最大值是___.
已知X2+Y2+8X+6Y+25=0 求代数式X2++XY+4Y2分之X2-4Y2 减X+2Y分之X的值
已知2x-3*根号(xy)-2y=0(x>0),则x2+4xy-16y2除以2x2+xy-9y2的值是多少?
已知:(x+y)2=1,(x-y)2=17,则x2+y2=___,xy=___.
已知x+y=4,xy=2,求x2+y2+3xy的值.
已知x2+y2-2x+4y+5=0,求(x^4-y^4)/(2x^2+xy-y^2)·[(2x-y)/(xy-y^2)]
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知实数x、y满足x2+4xy+4y2+x+2y-6=0,则x+2y的值为______.