Question

In an arithmetic sequence, find a50 when a1=7 and d=5

a. 495
b. 252
c. 275
d. 349

Answer 1

An arithmetic sequence is an ordered list of numbers where the next number is found by adding the same amount to the number before. (2,5,8,11... is one where you add 3 to get the next number)
The equation for arithmetic sequence is

`A_(n) = A_(1) +(n-1)d`
where
`A_(n)` is the "n th" number in the sequence
(
`A_(1)` is the first number in the sequence)
d is the number you add to get the next number


`A_(n) = A_(1) +(n-1)d`

`A_(50) = 7 +(50-1)(5)`

`A_(50) = 7 +(49)(5)`

`A_(50) = 7 +245`

`A_(50) =252`

The answer is B. 252