Answer:
Explanation:
the school did not have a year book before 2010
in 2010 there were 500 year book.
Into 2014, there were 1000 year book sold.
The increase in the number of textbooks sold per year is linear, hence, it is in arithmetic progression.
The formula for the nth term of an arithmetic progression is
Tn = a+(n-1)d
Where
a is the first term of the series
n is the number of terms
d is the common difference
From the information given,
a = 500 because it is the number of books for the first year
n = x = 5 because there are 5 terms(in years) from 2010 to 2014
Tn = 1000 because it is the number of books in the last year.
d = y = common difference or number of year book sold per year. Therefore, the linear function that represents the number of year book sold per year will be
1000 = 500 + y(x-1)