Question

Find an equation for the nth term of the arithmetic sequence.

-20, -16, -12, -8, .

Answer 1

a n =?
If the arithmetic sequence is:-20, - 16, - 12 , - 8 ...
a 1 = -20, d = 4 ( a 2 = -20 + 4 = -16, a 3 = -16+4 = -12,...)
And the formula for nth term is:
a n = a 1 + d (n -1)
a n = -20 + 4( n -1) (n=1.2.3...)