## Calculus (3rd Edition)

$$g_{xxyz}= 360 x^2y^4z^5 .$$
Since $g(x,y,z)=x^4y^5z^6$, then we have $$g_x= 4x^3y^5z^6, \quad g_{xx}= 12x^2y^5z^6 .$$ Then, we have $$g_{xxy}= 60x^2y^4z^6, \quad g_{xxyz}= 360 x^2y^4z^5 .$$