Respuesta :
Answer:
[tex]a_n=19+(n-1)(-5)[/tex]
Step-by-step explanation:
The explicit formula for an arithmetic sequence is [tex]a_n=a_1+(n-1)d[/tex] where [tex]a_n[/tex] is the [tex]n[/tex]th term and [tex]d[/tex] is the common difference.
In this problem, we can see that the first term of the sequence is [tex]a_1=19[/tex] and the common difference is [tex]d=-5[/tex] since 5 is being subtracted each consecutive term.
Therefore, the explicit formula that describes the given arithmetic sequence is [tex]a_n=19+(n-1)(-5)[/tex]
Answer:
option 2
Step-by-step explanation:
Let { a1, a2, a3, a4, ... } be the sequence.
now the 1st term (a1) will have a value when n = 1.
similarly, all the other terms will have the values given when we substitute their respective n values into the explicit formula or fibonacci sequence.
thus, check if the 1st term is 19 by using option 2
an = 19 + (n-1)(-5)
an = 19 + (n-1)(-5) ....n = 1
an = 19 + (n-1)(-5) ....n = 1 a1 = 19 + (1-1)(-5) = 19 + 0 = 19. so it's accurate so far.
next, check a2 where n = 2.
a2 = 19 + (2-1)(-5) = 19 - 5 = 14. ....
n = 3
a3 = 19 + (3-1)(-5) = 19 - 10 = 9.
hence the conclusion from this pattern.