please help me answer this question thanks

Let F(x, y, z be a function whose partial derivatives are continuous around a point P and nonzero at P. Hence, we know that each of r, y, z is a function of the other two around the point P, i.e. x = f(y, z), y = g(x, =), z = h(x,y). Show that at the following holds P Of ag Oh =-1 dy Oz ax