Question

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

-3, -5, -7, -9, ...

an = -3 - 2
an = -3 + -2(n)
an = -3 + -2(n + 1)
an = -3 + -2(n - 1)

Answer 1

an = -3 + -2 (n) is the answer. To verify this, start replacing the"n" with numbers like so: 0, 1, 2, 3, 4, 5....etc

Answer 2

1) To find out common equation for this sequence, it must be used n=1;2;3;4... etc.
2) to count a₁ use n=1. It is correct only for row  $a_n=-3+-2(n-1)$  result is (-3)
3) if to verify others value for n: