计算:1/(x-y)+1/(2y-2x)
计算:1/2x-1/x+y×(x+y/2x-x-y)
计算:1/(2x) - 1/(x+y)((x+y)/(2x) - x - y)
(2x+y)(x+3y-1)计算
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
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
1、x(x-y)(x+y)-x(x+y)^2
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)
已知x=2+根号3,y=2-根号3,计算代数式(x+y/x-y-x-y/x+y)乘以(1/x^2-1/y^2)
计算(x-2y-1)(x-2y+1)-(x-2y-1)²
计算:(x-2y)(1+x+2y+4y^2+2xy+x^2)
计算:(2/3x√9x+6x√y/x)+(y√x/y-√1/x)
利用因式分解计算1/2x(x-y)^2-1/5y(x-y)