Write a formula for the general term (the nth term)of the arithmetic sequence. Then use the formula for $r a _ { n }$ to find $a _ { 20 }$ , the 20th term of the sequence.
-$2,8,14,20,26 , \ldots$
A) $a _ { n } = 6 n - 4 ; a _ { 20 } = 116$
B) $a _ { n } = 6 n - 2 ; a _ { 20 } = 118$
C) $a _ { n } = 4 n - 2 ; a _ { 20 } = 78$
D) $a _ { n } = 4 n - 6 ; a _ { 20 } = 74$

Question

Quizplus · Accepted Answer

The common difference $d$ in the sequence is $8 - 2 = 6$. The first term $a_1 = 2$. The formula for the nth term of an arithmetic sequence is $a_n = a_1 + (n - 1)d$. Substituting $a_1 = 2$ and $d = 6$ gives $a_n = 2 + (n - 1)6 = 6n - 4$. For $a_{20}$, substitute $n = 20$ into the formula to get $a_{20} = 6(20) - 4 = 120 - 4 = 116$.

Write a Formula for the General Term (The Nth Term)of ranr a _ { n }ran​

Write a Formula for the General Term (The Nth Term)of $r a _ { n }$