Remember that X will always be one up or down depending on if there is a - or not (if it is just an x) and one over! Hope this helps
This is a geometric sequence with a common ratio of 2
an = a1 * r^(n - 1)
n = term to find = 21
a1 = first term = 0.05
r = common ratio = 2
now we sub
a21 = 0.05 * 2^(21 - 1)
a21 = 0.05 * 2^20
a21 = 0.05 * 1048576
a21 = 52428.80 <==== after working 21 days
Answer:
3000 books.
Step-by-step explanation:
Let x be total number of books.
3% is 3/100.
So:
3x/100=90
3x=9000
x=3000 books
