The recursive formula for an arithmetic sequence is an = an - 1 + d.

If the common difference is - 11 and a4 = 6, what if the value of a5?

A) - 5

B) 5

C) 17

D) - 17

If an is a5

and

an-1 is a4

then using your recursive formula for an arithmetic sequence

an=an-1 + d

then

a5=a4+d

now, a4 = 6 and common difference "d" is d=-11

hence

a5=6 - 11

6-11 = - 5

any questions?

A) - 5 should be your answer