由x2-6xy+9y2=4,得(x-3y)2=4,
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2x-3*根号(xy)-2y=0(x>0),则x2+4xy-16y2除以2x2+xy-9y2的值是多少?
X2+Y2+8X+6Y+25=0 求代数式(x2-4y2/x2+4xy+4y2)-x/x+2y
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x+y=4,xy=2,则x2+y2+3xy=______.
已知x+y=4,xy=2,求x2+y2+3xy的值.
设A=2x2-3xy+y2+x-3y,B=4x2-6xy+2y2+4x-y,若|x-3a|+(y+3)2=0,且B-2A
已知x2-3xy-4y2的绝对值+2倍根号x2+4xy+4y2-1=0 求3x+6y的值
A=4x2-2xy+4y2,B=3x2-6xy+3y2,且|x|=3,y2=16,|x+y|=1,求4A+[(2A-B)
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知x2+y2-4x+6y+13=0,求x2-6xy+9y2的值.
已知X2-2x+y2+6y+10=0,求(x2-2xy)/(xy+y2)的值