已知2x-y-3 ≤ 0,4x+5y-27
已知2x-y-3 ≤ 0,4x+5y-27
已知x,y>0 2x+y+3=xy 求5x+4y最小值
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
已知 x y 满足约束条件 x-y+5≥0 x+y≥0 x≤3 z=2x+4y的最小值为
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知|2-x|与|x-y+4|互为相反数,求代数式3(x-y)-5(x-y)-3(x-y)+(y-x)-4(x+y)+3
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知x^3+xy^2+x+x^2y+y^3+y=0,求5x-6y/3x+4y的值.
已知X,Y,满足(X+3Y)(X-3Y)=-10(Y^2-6/5)和2X(Y-1)+4(1/2X-1)=0
已知实数x,y满足条件x≥0,y≥x,3x+4y≤12,则(x+2y+3)/(x +1)的最大值是
已知(x+2)^2+|x+y+5|=0,求3x^2y-[2x^2y-(2xy-x^2y)-4x^2]-xy
已知(x+2)^2+|x+y+5|=0,求3x^2y+{-2X^2y-[-2xy+(x^2y-4x^2)]-xy}