# How do you write a rule for the nth term of the arithmetic sequence given #a_20=240, a_15=170#?

##### 2 Answers

Jul 20, 2017

#### Explanation:

Hence **..........(A)**

and **..........(B)**

Subtracting (B) from (A),

and hence putting this in (B), we get

or

Hence

#=-26+14n-14=14n-40#

Jul 20, 2017

#### Explanation:

So for the

To check out answer let's calculate

Which is true.