已知z=f(x^3-y^3,xy),求偏导
已知三个数x,y,z,满足xy/x+y=-2,yz/y+z=4/3,zx/z+x=-4/3,求(xyz)/(xy+yz+
已知3x-y+2z=x+2y+3z=0,求(3x^-xy+2y^)/(2x^+4xy+y^)值?
f(x+y,xy)=x²+y²,则f﹙x,y﹚=?函数z=2xy-3x²-3y²
已知xy/x+y=3,yz/y+z=2,zx/z+x=1,求y的值
设z=f(x,y)是由方程e^z-Z+xy^3=0确定的隐函数
1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-
已知实数x.y.z满足x+y=5及z的2次方=xy+y-9则x+2y+3z=?
已知实数x,y,z,满足x+y=5,z²=xy+y=9,求x+2y+3Z的值
已知x y z 满足x+y=5,z²=xy+y-9,求x+2y+3z的值
已知实数x,y,z满足x-y=5,z^2=-xy-y-9,求x-2y+3z的值
已知实数x,y,z满足x²-6xy+10y²+4y+|z²-3z+2|+4=0,求(x+y
已知x/3=y/4=z/6,求(xy+yz+xz)/(x²+y²+z²)