Find the first partial derivatives of the function.\
f(x, y, z) = xz - 3x$^8$y$^6$z$^9$\
f$_x$(x, y, z) = \
f$_y$(x, y, z) = \
f$_z$(x, y, z) = \
Find the first partial derivatives of the function.\
f(x, y) = x$^4$y$^7$ + 3x$^5$y\
f$_x$(x, y) = \
f$_y$(x, y) =