To work out a term, replace the n with the position in the sequence, e.g. The 1st term is (4 x 1) - 5 which is - 1.

The 4th term... Replace the 1 with a 4 so you have (4 x 4) - 5.

Another way to check your answer in these questions is to look at what the n is multiplied by. In this case we have 4n, so we have a sequence which increases by 4 each time.