find the rule for the Nth term of the arithmetic sequence. 11/2, 25/6, 17/6, 3/2, 1/6.....

If you change the denomators to 6, you should notice the numerators follow the sequence:

33,25,17,9,1,...which is an arithmetic sequence with a common difference of -8

so term(n) = -8n + k

since for n=1 term(1)=33, k must be 41

so term(n) = -8n + 41