Exercise 48 Page 279

To find certain terms in a sequence described by an explicit formula, substitute the number of the desired term into the given formula to get the term's value. We can find the $\text{second},$ $\text{fourth},$ and $\text{eleventh}$ terms of the sequence by substituting $2,$ $4,$ and $11$ for $n$ into the above formula. Now, let's do the same thing for the $\text{fourth}$ and $\text{eleventh}$ terms.

$n^{\text{th}}$ term	$\text{-}11+(n-1)(2)$	$A(n)$
$2$	$\text{-}11+(2-1)(2)$	$\text{-}9$
$4$	$\text{-}11+(4-1)(2)$	$\text{-}5$
$11$	$\text{-}11+(11-1)(2)$	$9$

The second, fourth, and eleventh terms are $\text{-}9,$ $\text{-}5,$ and $9.$