化简-12xy^2*1/3x^3y^4-x(2xy^2)^3

因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) 化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] 化简-12xy^2*1/3x^3y^4-x(2xy^2)^3 化简-12xy^2*1/3x^3y^4-x(2xy^2)^3 XY(XY+3)+(XY+4)+4(X+Y+1)-(X+Y+2) 化简2(x²y+xy)-3(x²y-xy)-4x²y 化简 2（xy-xy²+3）-（-4xy²+xy-1） 其中,x等于--4,y等于-3 化简：2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy}化简：2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy} 已知X+Y=3,XY=-1,求2(X-Y)^4-9(X-Y)^2+12XY 化简:-x(2)-(2xy) *9x(2)-9xy(3)+12x(4)y(2)/(3xy)谢谢! 5x^2y-3xy^2+4xy-14xy^2+4xy-2x^2y（化简） 化简!1、（x^2-xy）+xy+y^2 2、3（x^2-xy）-xy+y^2 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 若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= x-y=1,xy=2.求：(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 .已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 (-2xy+2x+5y)-(3xy+2y-2x)-(x+4y+xy)其中x-y=4xy=-1