Answer:
= - 5n - 2
Step-by-step explanation:
There is a common difference between consecutive terms, that is
- 12 - (- 7) = - 17 - (- 12) = - 5
This indicates the sequence is arithmetic with n th term
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = - 7 and d = - 5, then
= - 7 - 5(n - 1) = - 7 - 5n + 5 = - 5n - 2
Answer:
9 + 3 + 1 + ......... = 13.5
Step-by-step explanation:
The series 9 + 3 + 1 + is the sum of an infinite geometric sequence. The first term of the series is 9 while the common ratio is 1/3;
to obtain the common ratio we obtain the quotient of any two successive terms, 3/9 or 1/3.
The sum of an infinite geometric series with first term a and common ratio r is given by;
Plug in the values of a and r into the formula;
