y=2x-2 y=5x^2-4x y=-x^2 y=6/x 分别都是什么函数?求正确率
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
求函数f(x,y)=(6x-x^2)(4y-y^2)的极值
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知4x=9y求(1)x+y/y (2)y-x/2x
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*
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x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
求函数f(x,y)=4(x-y)-x^2-y^2的极值
求函数f(x,y)=4(x-y)-x^2-y^2 的极值?
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
求函数y=\x-1\+\x-2\+\x-3\+\x-4\+\x-5\+\x-6\+.+\x-10\的最小值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²