还是一道 亲们 点(x^2+2xy+y^2)/(5x^2-4xy)÷(x+y)/(5x-4y) +(x^2-y)/x我吃

[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y* 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8 (x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy) （xy-x^2)乘以(xy)/(x-y) 计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2 （x^2+xy/x-y)/（xy/x-y)计算 x^2y+4xy+4y 谁帮我化简：[(x+y)(x-y)-(x+y)^2-2y(x-y)-2xy]÷xy x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?