2xy^2*(3xy-1/2x^2)= 2ab*5ab^2*3a^2b= 3k(2k-5)+2k(1-3k)=52 k=?(-5/2xy)*(2/3xy^2-2xy+4/3y)

(-3xy+2xy)-(4xy+xy) 2xy-xy-(-3xy)= 3xy(x^2-xy^2+xy)-xy^2(2x^2-xy+2x) 化简:xy分之3x^2+2xy-xy分之2x^2-xy= 已知（x+1）*（x+1）=-Iy-1I,求2（xy-（5xy）*（5xy））-3（（xy）*（xy）-xy） ( )-(x^2+3xy)=-xy-1/3y^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 [6xy-3(xy-1/2x的平方y]/3xy=? 计算（-3分之1xy²）²×[xy（2x-y）+xy²]= 2x²y-3(2xy-xy)-xy 因式分解X^3-2xy+xy^2 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 已知1/x-1/y=2,求3x+7xy-3y/2x-3xy-2y答案是1/x-1/y=2(y-x)/xy=2 得：x-y=-2xy(3x+7xy-3y)/(2x-3xy-2y)=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy)=xy/(-7xy)=-1/7 谁能帮我解释一下=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy) 是怎 1-(3xy-x)+【-2(2x+3xy)】 因式分解x^3+2xy-x-xy^2= 计算3xy[2xy-x(y-2)+x-1] 3xy²-[xy-2(xy-3/2x²y)+3xy²]+3xy²,其中x=3,y=-1/3 化简求值 （-3x^y+2xy)-( )=4x^+xy