-3(2x^2-xy)-4(-6+xy+x^2)其中x,y满足(x+2)^2+丨y-3丨=0

(-3xy+2xy)-(4xy+xy) xy-2{xy-[3x^2y-(4xy^2+0.5xy)]+4x^2y}+6xy^2 （X-3xy+4xy-y）-[-2x-2（xy-3/2xy）-y]+6xy的过程 -3(2x^2-xy)+4(x^2+xy-6) 4(x²+xy-6)-3(2x²-xy) -3(2x²-xy)+4(x²+xy-6) 5x^3y*(-3y)^2+(-6xy)^2*(-xy)+xy^3*(-4x^2) 3xy-4xy-（-2xy） 3xy-4xy-（-2xy） 3xy(x^2y-xy^2+xy)-xy^2(2x^2-6xy+2x)过程 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 3xy(x^2-xy^2+xy)-xy^2(2x^2-xy+2x) （-3x^y+2xy)-( )=4x^+xy 2x²y-3(2xy-xy)-xy 因式分解X^3-2xy+xy^2 代数式求值!2x^2+3xy^2-4xy^2-6xy^2+3x-5-5x 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) 化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy]