求z=2x^2-8x-2y+9在D：2x^2+y^2≤1上的最大值和最小值

(x*x+2)(y*y+4)(z*z+8)=64xyz,求x,y,z 已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z x+2y=3x+2z=4y+z 求x:y:z 若x+y=6,xy=-8,求代数式(x+y-z)^2+(x+y-z)(x+y+z)-2·z(x-y) 若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 设由方程x+2y+z=e^(x-y-z)确定的隐函数为z=z(x,y),求d^2z/dx^2 x：y＝9：8 x：z＝3：2求x,y,z的值. 求z=2x^2-8x-2y+9在D：2x^2+y^2≤1上的最大值和最小值 x/10 = y/8 =z/9 求x+2y+3z/y-5z (x+2)*y=z+360 x*(y-8)=z-48 求x/y/z各是多少?最好有解法(x+2)*y=z+360x*(y-8)=z-48求x/y/z各是多少？ 已知(z-x)∧2-4(x-y)(y-x)=0求x+z-2y+8的值写错了(z-x)∧2-4(x-y)(y-z)=0求x+z-2y+8 已知:2X-3y+2z=0,x+4Y-9/2z=0求:X:Z的值.X:y:Z的值.X+2y+X/X+y+Z的值. 已知:2X 已知x+2y-z=8,2x-y+z=18 ,求8X+Y-Z的值 初二数学x+2y+4z=6,2x+y-z=9,求x+y+z=? 已知实数x,y,z,满足那么x+y=6,z^2=xy-9,求(x+y)^z