Question

find a23 in the sequence, -18,-34,-50,-66,......

Answer 1

Assuming that -18 is a1. You can see that d=-16

\(\Large\color{blue}{ \bf a_{n}=a_1+d(n-1) }\) in your case,

\(\Large\color{blue}{ \bf a_{23}=-18+(-16)(23-1) }\)

Answer 2

@solomonzelman tanks

Answer 3

yw