Find the term of an arithmetic sequence Exercise

Find the explicit term of the arithmetic sequence which first terms are the following.

−4, 2, 8, 14, 20, 26, 32, ...

−3, 1, 5, 9, 13, 17, 21, ...

3, 10, 17, 24, 31, 38,...

10, 7 ,4 ,1 ,−2 ,...

101, 97, 93, 89, 85, 81,...

−17, −14, −11, −8, −5, −2,...

21, 14, 7, 0, −7, ...