Given

V (x , y , z) = 10xyz - (x^2)z + 10y(z^2) -20

find the grad of V.

if i transfer to the form below the how do i associate the -20 with ?

10xyzax- (x^2)zay+ 10y(z^2)az-20

anyone able to help?

is the answer 10yz - 0 + 20yz ?

many thanks