Respuesta :
we are given
Let's assume total number of books =y
number of days =x
They started with 2 books
so, first term is 2
second term is 6
third term is 18
we can see that this is geometric series
so, firstly we will find common ratio
[tex] r=\frac{6}{2}= 3 [/tex]
total number of terms is x+1
now, we can find nth term
[tex] y=2(r)^{x+1-1} [/tex]
now, we can plug back r
we get
[tex] y=2(3)^{x} [/tex]...........Answer