已知x2+4y2+2x+4y+2=0,求x2-4y的值
已知方程x2 +y2+4x-2y-4=0,求x2 +y2的最大值
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x2+4x+y2-2y+5=0,求x,y的值.
1.已知X2+Y2-4X-6Y+13=0,求Y2-X2的值
已知x2-4x+y2-6y+13=0求x2+y2的值?
已知[(x2+y2)-(x-y)2+2y(x-y)]÷4y=1,求4x/4x2-4y2-1/2x+y的值,
已知x2+4y2+2x+4y+2=0,求x2-4y的值
已知x2+y2+4x-6y+13=0 求x2-2x\x2+3y2
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知2x+y=7,x2+y2=5,求(4x+2y)2-3x2-y2+2(1-y2)的值.
已知实数x,y满足x2+y2-2x+4y=0,则x2+y2的最小值是
已知x2-4x-1=0,求代数式(2x-3)2-(x+y)(x-y)-y2的值