1/2xy-{1/2xy-[1/3x^2y-(x^2y-xy)]+1/3x^2y}这是计算题,

1-(3xy-x)+【-2(2x+3xy)】 计算3xy[2xy-x(y-2)+x-1] 已知（x+1）*（x+1）=-Iy-1I,求2（xy-（5xy）*（5xy））-3（（xy）*（xy）-xy） (-xy^-1)^2*(-xy^-2)^-3/(-x^2y^3) y^3+xy^2+2xy+x^2-1 因式分解 5x^2y/-1/2xy*3xy^2 ( )-(x^2+3xy)=-xy-1/3y^2 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) 当x=3,y=3分之1时,求代数出3xy-[2xy-2(xy-2分之3xy)+xy]+3xy的值 5xy^2-{2x^y-[3xy^2-（xy^2-2x^2y）]/（-1/2xy）} 化简!1、（x^2-xy）+xy+y^2 2、3（x^2-xy）-xy+y^2 1/2xy(2/3xy²-2xy) 2xy(5xy的2次方+3xy-1) 2xy(5xy的2次方+3xy-1) （1）3xy-4xy-(-2xy)