Question

The explicit formula for a sequence is

Answer 1

Answer:

28

Step-by-step explanation:

Let n = 21, and evaluate the expression.

$a_n = -2 + \dfrac{3}{2}(n - 1)$

$a_{21} = -2 + \dfrac{3}{2}(21 - 1)$

$a_{21} = -2 + \dfrac{3}{2}(20)$

$a_{21} = -2 + \dfrac{3}{1}(10)$

$a_{21} = -2 + 30$

$a_{21} = 28$