Question

Given an arithmetic sequence with `a_23=- 372` and a common difference of `d=-8`, how do you find the value of a?

Answer 1

`-196`

Explanation:

`a_n = a_1 + (n - 1)d`

`a_23 = a_1 + (23 - 1)d`

`-372 = a_1 + (22)(-8)`

`-372 = a_1 - 176`

`-372 + 176 = a_1`

`-196 = a_1`