-12xy*3x^2y-x^2y*(-3xy)

(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y) x^2-xy-6y^2+3xy+y+2 xy=-2,x+y=3,求代数式（4xy+12y)+[7x-(3xy+4y-x)] 计算3xy[2xy-x(y-2)+x-1] 计算：3xy[2xy-x（y-2）+x] （-3x^y+2xy)-( )=4x^+xy x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 (x+y)(x-y)-(2xy+3y)平方 已知x-y=4xy，则2x+3xy-2yx-2xy-y xy(xy+1)+(xy+3)-2(x+y+2分之一）-(x+y-1)的平方 (-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)] 因式分解：(2x-y)(x^2+xy-2y^2) xy(x^2-xy)(-3xy^2)