若x^2-xy-2y^2-x-7y-6=(x-2y+m)(x+y+n) 求:m,n若x^2-xy-2y^2-x-7y-6=(x-2y+m)(x+y+n)求:m,n

1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 已知X+y=6,xy=7 求x^2y+xy^2=已知X+y=6,xy=7 x^2y+xy^2 化简求值x-4y/2x-7xy+3y×x-2xy-3y/2x+3xy-2y÷3x-6y/4x-4xy+y,其中：x=1999,y=-1 若x^2+xy+y=14,y^2+xy+x=28,求x+y 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 6（x-y)-7(xy)=21,2(x-y)-5(x+y)=-1 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,x-y=6,求xy(y^2+y)-y^2(xy+2x)-3xy的值. x^2-xy-2y^2+x+7y-6 x²+xy-2y²-x+7y-6 2x^+xy-y^-4x+5y-6=? 若x+y=4 x-y=6 求xy(x^2+y)-y^2(xy+2x)-3xy的值求值 若x=y=6,xy=2,求2x+3y-3xy+（4xy-3x）-（4y-7）的值 若x-y=5,xy=6,求x^2-xy^2和x^2y+xy^2 若x-y=5.xy=6,x^2y+xy^2等于多少 若x+y=5,xy=6,求x^2y+xy^2的值 若正实数x,y满足2x+y+6=xy,求xy的最小值. 若正实数X,Y满足2X+Y+6=XY,求XY的最小值.