(-3x^2y)x(-1/3xy^2)^3

计算3xy[2xy-x(y-2)+x-1] 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y 因式分解x^2y^2+x^2y+xy^2+3xy+x+y+1 xy(xy+1)+xy+3-2(x+y+1/2)-(x+y-1)^2因式分解 (-1/3xy)^2•[xy(2x-y)-2x(xy-y^2)] (-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)] XY(XY+3)+(XY+4)+4(X+Y+1)-(X+Y+2) 因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) （x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2 已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y) 已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y= 计算：(5-xy/x^3-x^2y)/(1-5/xy)^2*(y-x)^3 计算：1-2x+x^2/x-x^3*xy+x^2y/x-x^2 x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）² (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)答案应为-2x-x*x-3x， 若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 x-y=1,xy=2.求：(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值