y=-x^2-2x+3(-5≤x≤-2)
y=-3x,-2≤x
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
若变量x,y满足约束条件-1≤x:x≤y;3x+2y≤5,则z=2x+y的最大值为
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
已知x,y满足约束条件x−y+5≥0x+y≥0x≤3,则z=x+2y的最小值为( )
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
数学(x-y)^5*(y-x)^3*(x-y)^2
y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(