Question

Consider this sequence: -81, -54, -36, -24, … . The sequence is . The common ratio of the sequence is . The sum of the first five terms of the sequence is .

Answer 1

Answer:

The reason for the decreasing sequence is $\frac{2}{3}$

the sum of the sequence is -243

Step-by-step explanation:

Note that the numbers are decreasing so we will use the following formula to find the sum:

S∞=$\frac{t1}{1-q}$,

where t1 is equal to the first number of the sequence and q is the reason that gives the following results.

to find q this form is used;  

q= $\frac{t2}{t1}= \frac{-54}{-81} =\frac{2}{3}$

then we replace in the formula of the sum to find the total