x^2-4xy+4y^2-2x+4y

x^2y+4xy+4y (x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy) 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2 （-3x^y+2xy)-( )=4x^+xy xy-[x+2y+0.5(x-4)*(y-2)] (-x-2y)(x²-2xy+4y²) 化简(x²y-4y²)/(x²+4xy+4y²)*[(4xy)/(x-2y)+x 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- 已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)} [4/（x^2-y^2)+（x+y)/(xy^2-x^2y)] / (x^2+xy-2y^2)/(x^2y+2xy^2)