Question

Independent Practice

Find the second, fifth, and ninth terms of each sequence.


an=−5+(n−1)7a subscript n baseline equals negative 5 plus left parenthesis n minus 1 right parenthesis 7


A.
–4, –1, 3


B.
7, 28, 72


C.
12, 33, 61


D.
2, 23, 51

Answer 1

A.

2, 23, 51

Explanation:

Substitute 2, 5, and 9 for n in the function and simplify in each case.

a2=−5+(2−1)(7)=2 a subscript 2 baseline equals negative 5 plus left parenthesis 2 minus 1 right parenthesis left parenthesis 7 right parenthesis equals 2

a5=−5+(5−1)(7)=23 a subscript 5 baseline equals negative 5 plus left parenthesis 5 minus 1 right parenthesis left parenthesis 7 right parenthesis equals 23

a9=−5+(9−1)(7)=51 a subscript 9 baseline equals negative 5 plus left parenthesis 9 minus 1 right parenthesis left parenthesis 7 right parenthesis equals 51