6x-√(2xy)+xy=y^2 怎麼求导啊?

1-2/x+y=xy,4y+6x=xy.求xy的解? ( )*3xy=6x^2y+2xy^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 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 2x+y+6=xy,xy为正实数,求xy最小值 [6xy-3(xy-1/2x的平方y]/3xy=? （2xy平方+3xy平方）-（6x平方y-3xy平方）= 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) 已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值. 已知(xy)/(x+y)=6求(3x-2xy+3y)/(-x+3xy-y)的值. 3xy(x^2y-xy^2+xy)-xy^2(2x^2-6xy+2x)过程 已知X+y=6,xy=7 求x^2y+xy^2=已知X+y=6,xy=7 x^2y+xy^2 x^+2xy+y^+4=16 x^-2xy+y^=16 求(3xy+6y^)+|x^-(2xy+2y^-3x^)|的值 x^2-xy-6y^2+3xy+y+2 4xy-[(x²+5xy-y²)-(3xy-1/2y)]x=3,y=-6 若x-y=5,xy=6,求x^2-xy^2和x^2y+xy^2 已知x/y=2,求 [x^2-xy+3xy^2 ] / [ x^2+xy+6y^2]的值