Write a Formula for the General Term (The Nth Term) $$a _ { 1 } = - 7 , d = 0.5$$

Multiple Choice

Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for an to find a20,
the 20th term of the sequence.
- $$a _ { 1 } = - 7 , d = 0.5$$

A) $a _ { n } = - 7 n + 7.5 ; a _ { 20 } = - 132.5$
B) $a _ { n } = - 7 n + 0.5 ; a _ { 20 } = - 139.5$
C) $a _ { n } = 0.5 n - 7 ; a _ { 20 } = 3$
D) $a _ { n } = 0.5 n - 7.5 ; a _ { 20 } = 2.5$