Chapter 5 - Linear Functions - Get Ready! - Page 291: 14

$t_n = 2.5n - 5.5 $

So the formula for finding a term in a sequence is $ a+(n−1)d$ where $a$ is the first term, $n$ is the term number, and $d$ is the common difference. The sequence starts with the number $-3$, and the common difference is $2.5$ So let's plug the numbers into the formula. $t_n=2.5(n-1) - 3$ $t_n=2.5n-2.5-3$ $t_n=2.5n-5.5$