Question

the first term of an arithmetic sequence is equal to 200 and the common differencence is equal to -10. find the value of the 20th term​

Answer 1

The value for 20th term is 10.

Explanation:

First, you have to find the formula for the sequence.

`an = a + d(n - 1)`

`let \: a = 200,d = - 10`

`an = 200 - 10(n - 1)`

`an = 200 - 10n + 10`

`an = - 10n + 210`

Given that the formula of this sequence is an = -10n + 210. Next, you have to find 20th term :

`let \:n = 20`

`20th \: term = - 10(20) + 210`

`20th \: term = - 200 + 210`

`20th \: term = 10`

(Correct me if I am wrong)