Question

Consider this sequence: -81.-54, 36, -24....

Answer 1

Answer:

See below in bold.

Step-by-step explanation:

It looks like the third term  should be -36.

The sequence is geometric.

The common ratio is -54/-81 =  -36/-54 = -24/-36 = 2/3 .

The sum of the first 5 terms is

(-81) * (1 - (2/3)^5) / (1 - 2/3)

= -81 * 211/243 * 3

= -211.