### Home > CCA > Chapter 7 > Lesson 7.1.1 > Problem 7-15

7-15.

For parts (a) and (b), find a recursive equation in

*a*form for each sequence. (For a reminder about_{n}*a*form see the Math Notes box in Lesson 5.3.2.) For parts (c) and (d) find an explicit equation for each sequence._{n}108, 120, 132, …

, , , … 3741, 3702, 3663, …

117, 23.4, 4.68, …

*a*_{1} = 108*a**a _{n}*

_{+1}= a

*+12*

_{n}*a*_{(}_{n}_{ + 1)} = 2*a _{n}*

Is the sequence arithmetic or geometric?

Is the sequence arithmetic or geometric?