Answer:
-3
Step-by-step explanation:
Consider the geometric sequence:
[tex]b_1=-2\\ \\b_2=6\\ \\b_3=-18\\ \\b_4=54\\ \\....[/tex]
Note that
[tex]b_2=b_1\cdot q\\ \\b_3=b_2\cdot q\\ \\b_4=b_3\cdot q\\ \\...[/tex]
So,
[tex]6=-2q\\ \\-18=6q\\ \\54=-18q\\ \\...[/tex]
From all of these equalities we can state that
[tex]q=-3[/tex]
Answer:
r = - 3
Step-by-step explanation:
The sequence is geometric if a common ratio r exists between consecutive terms.
6 ÷ - 2 = - 3
- 18 ÷ 6 = - 3
54 ÷ - 18 = -3
The sequence is geometric with common ratio r = - 3