Question

What is the value of the 19th term in the sequence -1, -5, -9, ...? -77 -73 -71 -22

Answer 1

All right i just earned that today! 
This is the formula An = A1 + ( n-1 )D 
You would take A19 = -1 + ( 19 - 1 ) -4 
-1 + 18(-4) 
-1 + -72
-73 
Hope that helped! 
:)