Answer:
a. it is arithmentic - this is because for each term there is a constant increase of 4, and the change between each term doesn't change
b. you need to find the nth term, by using the equation difference x n + 0th term: the difference is (+)4 and the 0th term is -9 (-5 is the 1st term, so to go one back we subtract 4 - the inverse operation), so the nth term is 4n -9. Now we do the inverse operation on 119 to see if it's a term (it is a term if it's an integer. So, first we do 119 plus 9 (inverse of - 9) to get 128, then divide it by 4 rather than multiplying. This gives us 32, and that tells us that 119 is the 32nd term of the sequence.