化简:-x(2)-(2xy) *9x(2)-9xy(3)+12x(4)y(2)/(3xy)谢谢!

(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y) （-3x^y+2xy)-( )=4x^+xy 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 已知2x+xy=10,3y+2xy=6.求4x+8xy+9y=? x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 已知x-y=4xy，则2x+3xy-2yx-2xy-y xy=-2,x+y=3,求代数式（4xy+12y)+[7x-(3xy+4y-x)] x*-2xy+3y*=9 4x*-5xy+6y*=30 （xy-x^2)乘以(xy)/(x-y) 化简4xy-3y²-3x²+xy-3xy-2x²+x²-2y² 计算3xy[2xy-x(y-2)+x-1] 计算：3xy[2xy-x（y-2）+x]