Solve for
:

Now if
, we have
and

On the other hand, if
, then
and

The slope is 2
Hopes this helps in any sort of way
Step-by-step explanation:
To find the formula for the nth term ,
First , find the common difference or common ratio.
Common difference =

Common ratio =

The common difference applies to the other given numbers for example :

this proves that it is an arithmetic sequence and the given formula for the nth term of an arithmetic sequence is
T_n =a(n-1)d
Where n = no of terms
a= first term
d= common difference