1) Find the 128th term for the sequence 9, 4, - 1, - 6, 11, ...

2) Find the 97th term for the sequence - 3, 6, - 12, ...

To determine an nth term of an arithmetic sequence, we use the expression an = a1 + (n-1) d where a1 is the first term in the sequence, n is the number of the term in the sequence and d is the common difference. For a geometric sequence, it is expressed an = a1r^ (n-1). We calculate as follows:

1. a128 = 9 + (128-1) (-5)

a128 = - 626

2. a97 = (-3) (-2) ^ (97-1)

a97 = - 2.377x10^29