Question

Write an explicit formula for the nth term of this sequence:

6, 11, 16, 21, . . .

1. an=5n+11

2. an=5n+1

3. an=21-5n

4. an=6n+1

Answer 1

Answer:

2)an = 5n + 1

Step-by-step explanation:

This is an arithmetic series.

6 , 11 , 16, 21 ,.....

First term = $a_{1}$ = 6

Common difference = d = second term - first term

                                = 11 - 6 = 5

nth term = $a_{1}+(n-1)*d$

             = 6 + (n - 1) * 5

            =  6 + n * 5 - 1*5

            = 6 +5n - 5

           = 6 - 5 + 5n

           = 1 + 5n