化简:[(-3x^2y^4)^2·x^3-2x·(3x^2y^2)^3·1/2y^2]÷9x^7y^8
化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方
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(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
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*y)+【-
9y=3x-(x-1),4(x+y)-(2x+4)=8y
x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2
【x-3y][x+y]-[x-2y][x +2y]-[x-y
[(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)
(x+3y-4)(2x-y)
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1