计算3x-2y-(9x-7y)+2(4x-5y)

计算(x-y)^7÷(y-x)^6+9-x-y)^3÷(x+y)^2 计算3x-2y-(9x-7y)+2(4x-5y) 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) 计算（4x^2y-9y)/(2x+3) 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x 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（2x-3y)(x+4y)-(3x+y)(x-2y)（2x-3y)(x+4y)-(3x+y)(x-2y) 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). (x-3y)(y+2x)-(4y-3x)(3x+4y)计算 计算：(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2 计算:(x-y)^2*(x+y)^3*(-x-y)^3*(y-x)^4 3x+2=y 5X+4=Y 7X+6=Y 9X+8=y 11x=y要如何计算 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