y²-x²/5x²-4xy除以x+y/5x-4y
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知A除以x²+4xy+4y²分之x²-y²=x+2y分之x+2y,当x=2,y
已知X+Y=2XY,求4X-5XY+4Y 除以X+XY+Y 的值
x²/xy-x/y
(x+y)²+4(x+y)-5
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
2x+y分之4x²-4xy+y²除以(4x²-y²)化简
已知x²+3xy-4y²=0,求(x-2y)除以(x+2y)的值
化简求值.(x-2y分之4xy 再加+x)除以4x³-x²y分之x²+4xy+4y
已知:x/y=4/5,求y²/(x²-xy+y²)的值
x²+xy/(x-4y)(x+y),其中x=4,y=-1
(-x-2y)(x²-2xy+4y²)