4+x²+y²/2≤xy+y 求x+y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
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2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
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2x+y=0,求x-2y/x²+xy*(x²-y²)/x²-4xy+4y
已知2x+y=0,求x-2y/x²+xy乘(x²-y²)÷x²-4xy+4y
(-x-2y)(x²-2xy+4y²)
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²的值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 快救救我~