Question

The sequence below shows the number of raffle tickets that Samantha sold each day during a month.

3,7,11,15…

Which one explicit formula models the number of tickets Samantha sold on day x?

Answer 1

C

Explanation:

You are looking for the arithmetic sequence.

`a_(n)` =
`a_(1)` + (n-1)d

In this case the formula is written:

t(x) = 3 + 4(x-1)

The 3 is the first term. The 4 is how much the sequence is increasing each time. (x-1) stands for the term we are looking for. If we were looking for the 15th term, we would have (15-1) in the parentheses.