A sequence has a common difference

Question

A sequence has a common difference of D=-4 so if A₂=-5 what is A₅? 

 

A. -9 

B. -13 

C. -17 

D. -21

 

Answer 1

The common difference is -4, so you will go down 4 each time.  If the second number in the sequence (A2) is -5, A3 would be -9 (-5-4).  A4 would be -13 (-9-4).  A5 would be -17 (-13-4).