若x>0,y>0,xy≡4,求证x+y≥4
已知xy大于0求证xy+1/xy+y/x+x/y大于等于4
若x>0,y>0,x+y>2,求证:1+xy
X>0,Y>0,X+Y=10,求证:XY≤25.
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
例4.设x,y∈R,求证:|x+y|=|x|+|y|成立的充要条件是xy≥0.
若(x-4y)(x+3y)=0 且xy>0 则分式x+3y/2x-y的值为
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
接着提问数学题!设x>0,y>0,求证1/2(x+y)^2+1/4(x+y)>=√xy(√x+√y)
已知x>y>0,xy=1,求证(x^2+y^2)/(x-y)≥2根号2
若x>1,y>0且满足xy=xy,xy=x
已知x的平方+y的平方-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)