若3X^2-7XY-6Y^2=0求2X/Y的值

若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值 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 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=6,xy=2,求2x+3y-3xy+（4xy-3x）-（4y-7）的值 若(3xy+2)^2+|7-x-y|=0,求代数式(5xy+10y)-[-5x-(4xy-2y+3x)]的值 若(3xy+2)+|7-x-y|=0,求代数式（5xy+10y）-[-5x-（4xy-2y+3x）]的值. 已知x/2=y/3（xy≠0）,求x²-2xy-3y²/x²-6xy-7y²的值 若2x+y=0,求(x^2+xy+y^2)/(2xy-x^2) 已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy 若集合{x,xy,lg(xy)}={0,|x|,y},求log8(x^2+y^2) 若两个正实数x,y满足x^2+2xy-3y^2=0,求x^2+xy+y^2/x^2-xy+y^2 求（3x^+y^-5xy）-【2x^-（-4xy-y^+7x^）】=? 求（3x^+y^-5xy）-【2x^-（-4xy-y^+7x^）】=? 若x+y=4 x-y=6 求xy(x^2+y)-y^2(xy+2x)-3xy的值求值 若(y-x)/xy=3,求分式(2x+3xy-2y)/(x-2xy-y)的值 若y-x/xy=3,求分式2x+3xy-2y/x-2xy-y x-y+3xy=0 求2x+3xy-2y/x-2xy-y的值 已知X-XY-2Y=0求2X+3XY-Y/X-2XY+5Y