Could someone please help me with this question

Finish the proof of Theorem 5.1.13. Let f: D - R and f: D - R , and let c be an accumulation point of D.19 If lim f(x) = L, lim g(x) = M , and k E R , then a-+ c 1. lim (fg) ) (x) = LM , ads a sastrail a sued Jon asab ) (3) 2. lim (kf)(x) = kL . 3. Furthermore, if g(x) ot = 0 for all x E D and Mot = 0 , then lim x -+ C ( : ) (2 ) =