Question

What is the 32nd term of the arithmetic sequence where `a_1 = -31` and `a_9 = -119`?

Answer 1

`a_32 = -372`

Explanation:

We have
`a_1 = -31`

For `a_9:`
`rarr a_9 = a_1 + (n-1)d) = -119`

`-31 +8d = -119`

`8d = -119+31 = -88`

`d = -11`

For `a_32`

`rarr a_32 = a_1 +(n-1)d`

`a_32 = -31 + 31 xx-11`

`a_32 = -372`