In an arithmetic progression, the sum of the first \(n\) terms, denoted by \(S _ { n }\), is given by
$$S _ { n } = n ^ { 2 } + 8 n .$$
Find the first term and the common difference.
In a geometric progression, the second term is 9 less than the first term. The sum of the second and third terms is 30 . Given that all the terms of the progression are positive, find the first term.