4x²+9y²-4x-6y+2=0,求1/√xy
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
已知X²+Y²+X²Y²-4XY+1=0 求:(X-Y)^2008-(XY)^2
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知|x²-2xy-8y²|+2√x²-4xy+4y²-1=0,求3x+6y的值
4x²+9y²-4x-6y+2=0,求1/√xy
2x+y=0,求4x²+2xy(x+y)+y³
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x²+y²-2x+4y+5=0,求x²-9y²/x²+6xy+9y
已知:x²-6xy+9y²=0,求代数式3x+5y/4x²-y²×(2x+y)的
(4x-2y-1)²+√xy-2=0,求4x²y-4x²y²+xy²
求x²+y²-2x+4y+1的最小值 求x,y的值 x²+2xy+4x-12y+22=0