2x+3y-4xy=0(4y-2)x=3yx>0,y>0,因此4y-2>0 y>1/2x=3y/(4y-2)3x+2y=9y/(4y-2) +2y=(8y²+5y)/(4y-2)=[8y²-4y+9y -(9/2) +(9/2)]/(4y-2)=2y+ 9/4 +(9/2)/(4y-2)=(2y-1) +(9/4)[1/(2y-1)] +13/4y>1/2 2y-1>0,...