The following are the choices on this question:
A.6
B. 39
C. 26
D. 12
The answer is option D. 12.
Check this out:
S=n² + n
S= 12² + 12
(you can get the square of 12 by multiplying 12 by itself: 12 × 12)
S=144 +12
S=156
Answer:
subtract 20 on both sides then that should give you the answer
Step-by-step explanation:
Given:
First term of an arithmetic sequence = 5
Second term = 3
To find:
The explicit formula for the given arithmetic sequence.
Solution:
We have,
First term: 
Second term: 
Common difference is



Now, the explicit formula for an arithmetic sequence is

where, a is first term and d is common difference.
Putting a=5 and d=-2, we get

It can also be written as


Here, n is an integer greater than or equal to 1.
Domain is the set of input values.
Therefore, the explicit equation is
or
and domain is all interest greater than or equal to 1.
................................................
The answer is 15.
Pretty sure it's A. (X times .5 equals Y)