This is an example of an arithmetic sequence, which progresses from a single given number and progression of the terms.
For example in the given what is the 1st term?
You substitute 1 to n
t1= 3(1) + 2 = 5
Hence what is the 5th term then?
You again substitute the unknown to the value of 5.
t5=3(5) +2 = 17
