Question

18 PTS!! What is the 400th term of the sequence below when using the explicit formula
aₙ=a₁+(n-1)•d?

79, 82, 85, 88,...

A. 1273
B. 1279
C. 1276
D. 1282

Answer 1

Answer:

$\huge\boxed{\sf a_{400}=1276}$

Step-by-step explanation:

Sequence:

79, 82, 85, 88, ....

Explicit formula:

$a_n=a_1+(n-1)d$

Where,

• $a_n = a_{400$ (the term that is to be found)
• $a_1 = 79$ (the first term)
• $n = 400$
• $d = 3$ (difference between first and second term)

Put the givens in the above formula

$a_{400}=79 +(400-1)3\\\\a_{400}=79 + 399\times3\\\\a_{400}=79+ 1197\\\\a_{400}=1276\\\\\rule[225]{225}{2}$