Question

Determine whether each sequence is a geometric sequence. If yes, then state the common ratio.

120, -60, 30, -15,...

Answer 1

120 ,-60 , 30 , -15 1

Answer 2

This is a geometric sequence with a common ratio of -1/2

Explanation:

Take the second term and divide by the first term

-60/120 = -1/2

Take the third term and divide by the second term

30/-60 = -1/2

Take the fourth term and divide by the third term

-15/30 = -1/2

This is a geometric sequence with a common ratio of -1/2