化简3x^2-9x-12/x^2+2x+1 xy-x-y+1/y^2-2y+1
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
1、x(x-y)(x+y)-x(x+y)^2
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
(x+y-2xy)(x+y-2)+(1-xy)²
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
9xy(x-y)(x+1)-3y(x-y)(3x+2y)+6y的平方(x-y)(x+1),因式分解
【(x-y)^3(x^1/2+y^1/2)^-3+3(x根号y-y根号x)】/(x根号x+y根号y)+(2xy根号xy-
化简 (x+y)(x²-xy+y²) ; 3(2x-1)(x+6)-5(x-3)(x+6)
(1)(x^2/x)-y-x-y
x+y=1,xy=-1/2,求x(x+y)(x-y)-x(x+y)2
计算3xy[2xy-x(y-2)+x-1]
【(1)/(x-y)+(1)/(x-y)】÷(2x)/(x²-2xy+y²)