计算:(1).(2x-3y)/(y-x)-(x+2y)/(x-y) (2).[5m/(m-3)+2m/(m+3)]*(m^2-9)/m

计算:(x+3y)(2x-y) 计算:(2x-3y)(x+y) 计算:(-x-2y) * (3x-y) 计算：(x+y)-3(x-2y). 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x 计算(x+y)(x+y)^2(-x-y)^3 3x(x-y)+2y(x-y) 计算 计算：x+2y/x-y+2x/y-x-3y/x-y 计算x^2y^-3（x^-1y）^3 (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) 计算:y×(y/x)^3÷[-(x^2)/y]^-2 计算：y(x-y)^2+(y-x)^3=? 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^-1 - y^-1)/(x^-2 - 3x^-1 y^-1 + 2y^-2) 计算(x+y-1)^2