Work out the nth term of the sequence 3, 7, 11, 15, ...

This is an example of an arithmetic series because each term is +4 from the previous term.This means for the "nth term" we start with +4n.Now we take a specific term from the sequence e.g. 3 (1st term) and see what constant we need to add to our "nth term".Since 3 is the 1st term, n in this example is equal to 1.So 4x1 = 4 but we have 3 therefore we need a constant of -1 to complete our "nth term" rule.Therefore the nth term is 4n - 1