If `u = log (x^(3) + y^(3) + z^(3) - 3xyz)`, then `(x + y + z)(u_(x) + u_(y) + u_(z))` is equal to

If u=log (x^(3) + y^(3) +z^(3) - 3xyz) , then (del u)/(del x) + (del u)/(del y) + (del u)/(del z)=

If u = log ((x ^ (2) + y ^ (2)) / (x + y)), prove that x (u) / (x) + y (u) / (y) = 1

If u = log ((x ^(2) y + y ^(2) x)/(xy)) then x (del u)/( del x) + y (del u)/(del y)=

If U(x,y,z) = log(x^(3) + y^(3) +z^(3)) find (del U)/(dx) + (del U)/(dy) + (del U)/(dz)

If x + y + z = 0 , then ( x + y - z)^(3) + ( y + z - x)^(3) + (z + x - y) ^(3) = k (xyz) , where k is equal to :

If x:y:z=3:3:5 and x^(3)+y^(3)+z^(3)=1728 , then find (x-y+z)