The dimension of the poster she has to decorate is 113 feet by 214 feet. It is in the shape of a rectangle. She can find the area by using the formula for the area of a rectangle.
The series shown is an geometric series and the explicit formula is given by: an=ar^(n-1) where a=first term n=number of terms r=common ratio from the sequence: a=30 r=5 thus the explicit formula will be: an=30(5)^(n-1) hence the answer is: an=30(5)^(n-1)
