Chapter 7 - Exponents and Exponential Functions - 7-8 Geometric Sequences - Practice and Problem-Solving Exercises - Page 470: 20

Geometric, the common ratio is -1.

You have the sequence: -7, 7, -7, 7. Find the common ratio by using the formula: R=$\frac{a2}{a1}$,R=$\frac{a4}{a3}$.Plug in the values to get the ratios. r=$\frac{-7}{7}$=-1 r=$\frac{-7}{7}$=-1 There is a common ratio, r=-1. So the sequence is geometric.