已知x,y满足x+3y=5,3x+y=-1,则x-y=?
已知实数x,y,满足x-√x-1=√y+3-y,则x+y最大值是?
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
已知X和Y满足3X+4Y=2,X-Y-1/7
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
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x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y
设变量xy满足 x+y-3 x-y+1 3x-y+5 z=x+y/x
x>1,y>0,且满足xy=x^y,x/y=x^3y,求x+y
已知变量x,y满足约束条件:x+y≧1,y≦3,x-y≦1,若z=Kx+y最大值为5,则实数k
已知x,y满足方程组{x+3y=5 3x+y=-1}则代数式x-y的值为___
已知变量x,y满足约束条件 y≤2 x+y≥1 x-y≤1 则z=3x+y的最大值是