Question

Given the sequence 128, −32, 8… , which of the following statements is TRUE? *
A. The sequence is a geometric sequence with a common ratio of −4.
B. The sequence is an arithmetic sequence with a common difference of −4.
C. The sequence is a geometric sequence with a common ratio of -1/4.
D. The sequence is an arithmetic sequence with a common difference of -1/4

Answer 1

Answer:

C

Step-by-step explanation:

Because the ratio between 128 and -32 is the same as the ratio between -32 and 8

Answer 2

Answer:

C

Step-by-step explanation:

The sequence has a common ratio r between consecutive terms

r = $\frac{a_{2} }{a_{1} }$ = $\frac{-32}{128}$ = - $\frac{1}{4}$

r = $\frac{a_{3} }{a_{2} }$ = $\frac{8}{-32}$ = - $\frac{1}{4}$

Thus the sequence is geometric with common ratio r = - $\frac{1}{4}$