The arithmetic progression is specified by the conditions c1 = 2, c n + 1 = cn-4. Find c5

Knowing which number is in the first place in a given sequence, as well as the formula by which this progression is given, we will successively find the terms of this progression from the second to the fifth.

We find the member of the sequence that is in second place:

c2 = c1 – 4 = 2 – 4 = -2.

Find the third-place member of the sequence:

c3 = c2 – 4 = -2 – 4 = -6.

Find the fourth member of the sequence:

c4 = c3 – 4 = -6 – 4 = -10.

Find the fifth member of the sequence:

c5 = c4 – 4 = -10 – 4 = -14.

Answer: c5 = -14.