Question

Which of the following correctly uses the explicit formula, An=14+(n−1)⋅12
𝐴
𝑛
=
1
4
+
(
𝑛
−
1
)
⋅
1
2
, to find the 9th term of the described arithmetic sequence?(1 point)
Responses

414
4
1
4
4 Start Fraction 1 over 4 End Fraction

834
8
3
4
8 Start Fraction 3 over 4 End Fraction

434
4
3
4
4 Start Fraction 3 over 4 End Fraction

814
8
1
4
8 Start Fraction 1 over 4 End Fraction

Answer 1

A9 = 1/4 + (9−1)·1/2 = 1/4 + 8·1/2 = 1/4 + 4 = 4 1/4 (or 17/4).
So the correct choice is 4 1/4.