Sorry im a little late but here's how i did it.
Hope this helps! :)
<span>-3(1+6r)=14-r
-3 - 18r = 14 - r ...expand by using distributive property
-3 -17r = 14 ...add (r) to both sides
-17r = 17 ...add (3) to both sides
r = -1 ....divide both sides by (-17)</span>
Common difference is +6 and I think nth term is 5 (pretty sure it's always the first term) and the second one im not so sure about I'm sorry.
The answer is 10 hope this helps