15. Find the next two terms in each sequence and also the formula for the nth term.
(a) 3, 5, 7, 9, , nth term:
(b) 2, 6, 10, 14, , nth term:
(c) 94, 90, 86, 82, , nth term:
(d) 2, 5, 10, 17, 26, , nth term:
(e) \[\frac{4}{1}\] , \[\frac{5}{4}\] , \[\frac{x+y}{y-z}\] , \[\frac{x+y}{y-z}\] , nth term: