Answer:
30?
Step-by-step explanation:
I think its 30 because 15*2 is 30 but I really don't know im sorry
Answer: 4.5 * 10^4
Step-by-step explanation:

factorising the first denominator
x²-2x-3 = x² -3x+x-3 = (x+1)(x-3)
(a) 
finding LCD
(b) LCD of (x-3)(x+1) and (x-3) is (x-3)(x+1)
(c)

(d)



F(n-1) = f(n) - 5, based off of the first one