4x^2-14xy+6y^2-7x+y-2
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
x^2y+4xy+4y
x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2
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)
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
xy=-2,x+y=3,求代数式(4xy+12y)+[7x-(3xy+4y-x)]
(x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy)
(xy-x^2)乘以(xy)/(x-y)
x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值
因式分解:8(x-2y)-x(7x+y)+xy.