Answer:
The reason for the decreasing sequence is
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∞=,
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=
then we replace in the formula of the sum to find the total