Find the common difference and the three terms in the sequence after the last one given.

Question

The numbers are (1/5), (23/15), (43\15), (21/5)

I can't find a common difference between these numbers.

Answer 1

We have to derive formula for general term here a_n = (3 + 20(n - 1))/15, or a_n = (20n -17)/15,

becouse terms creates arifmetic sequence with a₁ = 3/15 or 1/3 and common difference 20/15= 4/3.