(x-3y)·(-3xy)=?

(x-3y)·(-3xy)=? 【x(xy-xy)-y(x-xy)】÷3xy -x-3xy+y （-3x^y+2xy)-( )=4x^+xy x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? 当x-y=2xy时,求4x-3xy-4y/xy 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 由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少? (-3/2xy)·(2/3x²y-4xy²+4/3y)= 先化简,再求值：x^x+xy/x^x-xy^(y^y-xy/xy)除以(x+y),其中x=1/3,y=-3 f(xy,x-y)=x^2+3xy+y^2,则f(x,y)=? -1/3x²y²+xy=( )(xy-3) -xy-3/1y平方+(x平方=3xy) 【 】-【X平方+3XY】=-XY-1/3Y平方 ( )-(x^2+3xy)=-xy-1/3y^2 X+y=3 xy=-5 Xy=? 3X^2+XY+Y=15 求XY. ( )*3xy=6x^2y+2xy^2