PLZ HELP! 20 POINTS!
A student writes the arithmetic series 8 + 13 + ... + 43 in summation notation (pictured below)
A) Describe the error.

B) Find the sum of the arithmetic series

C) Write the explicit and recursive formulas for each term in the series. Be sure to label them.
I also attached the entire question below.

a) The error is that, the initial value is n=1 NOT n=3

b) The sum is

c)The explicit formula is  

The recursive formula is ,

Step-by-step explanation:

The given arithmetic series is  8 + 13 + ... + 43.

The first term is , the  common difference is

The nth term is given by:

We substitute the values to get:

To find how many terms are in the sequence we solve the equation:

The summation notation is  

The error the student made is in the initial value.

It should be n=1 NOT n=3

b) The sum of the arithmetic series is calculated using:

We substitute o get:

c) The explicit formula we already calculated in a), which is

The recursive formula is given as:

We substitute d=5 to get:

4/7 + 8/15 = 1 11/105

Step-by-step explanation:

4/7 + 8/15 = 1 11/105

= (4/7 x 15/15) + (8/15 x 7/7)

= 60/105 + 56/105

= 116/105 = 1 11/105