计算:(x^2-2x+1-y^2)/(x+y-1)

计算：1/2x-1/x+y×（x+y/2x-x-y) 计算:1/(2x) - 1/(x+y)（(x+y)/(2x) - x - y） 1、x(x-y)(x+y)-x(x+y)^2 计算3x[xy-2x(1/y-x/3]+3y(x²-y²) (1)(x^2/x)-y-x-y (2x+y)(x+3y-1)计算 计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8 计算:(2/3x√9x+6x√y/x)+(y√x/y-√1/x) 计算:(-x-2y) * (3x-y) 1.计算(a^2+a+1)(a^2-a+1) 2.计算(x-y)(x+y)+(3x-2y)(2x+y)-x(6x-y) 计算:(x-y)^2*(y-x)^2*(x-y)^6 计算(x+y)(x+y)^2(-x-y)^3