Respuesta :
The first term is 5
Yes this a arithmetic sequence
The common difference is 7
Yes this a arithmetic sequence
The common difference is 7
Answer:
Find the first term:
The first term is 5
Is the sequence arithmetic?
Yes because (5 -7 = -2) (-2 - 7 = -9)
Find the common difference d:
The common difference is -7
Find the general term an:
[tex]a_{n}[/tex] = (first term) + ((nth term) -1) · (common difference)
[tex]a_{n}[/tex] = 5 + (n - 1) · (-7)
Find the 20th term:
[tex]a_{20}[/tex] = 5 + (20 - 1) · (-7)
= -128
Find the sum of the first 50 terms:
[tex]a_{50}[/tex] = 5 + (50 - 1) · (-7)
= -338
