Question

For the arithmetic sequence beginning with the terms (9, 14, 19, 24, 29, 34 ...), what is the sum of thefirst 23 terms?O a.) 1353o b.) 1472C.) 1725O d.) 1596SUBMIT MY ANSWER

Answer 1

There is an equation for getting the sum of a sequence but there are variables we first need to find.

Sn = (n/2)(2a + (n-1)d)

STEP 1

Getting variables.

Sn = Sum to a the nth ordinal.

n is an arbitrary number

a = first term

d = common difference = Tn - Tn-1 where Tn is the nth term

STEP 2

We substitute into the equation where

n = 23

a = 9

d = 14 - 9 = 19 - 14 = 24 - 19 = 5

`\begin{gathered} S_(23)=(23)/(2)(2(9)\text{ + (23-1)5)} \\ S_(23)=1472 \end{gathered}`

Therefore, the sum of the first 23 terms of the progression is 1472. Option B