What are the steps to find the first five terms and the term named in the problem?

Question

I’m horrible with fractions and don’t understand the steps to reach the correct answers. Trying to understand so I can make sure my son understands.

a_n = 11/8 + 1/2n

Find a₂₃

Answer 1

I assume you mean a_n = 11/8 + (1/2)n , the arithmetic series. In order to find the term, a₂₃, you need to plug in n= 23 to the expression:

a₂₃ = 11/8 + 23/2

In order to add the fractions, they must have the same denominator

The common denominator is 8 for 8 and 2, so multiply 23/2 * 4/4 to get 92/8 and add

11/8 + 92/8 = 103/8 or 12 7/8