Find the inverse transforms of the following functions:
(a) \(F_{1}(\omega)=6 \pi \delta(\omega)+6 \pi \delta(\omega-3)+6 \pi \delta(\omega-4)\)

(b) \(F_{2}(\omega)=4 \pi \delta(\omega)-j 6 / \omega+4 \pi \delta(\omega-2)\)

(c) \(F_{3}(\omega)=10 \pi \delta(\omega)-j 20 / \omega\)