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ratelena [41]
2 years ago
5

Which calculation should be used to calculate s9 for the arithmetic sequence an=3n-1

Mathematics
2 answers:
Ganezh [65]2 years ago
7 0

Answer: Choice A

S9 = (9/2)*(2+26)

===============================================

The formula is

Sn = (n/2)*(a1+an)

where

Sn = sum of the first n terms (nth partial sum)

n = number of terms

a1 = first term

an = nth term

In this case,

n = 9

a1 = 2 (plug in n = 1 into the formula an = 3n-1 and simplify)

an = a9 = 26 (plug n = 9 into the formula an = 3n-1 and simplify)

So,

Sn = (n/2)*(a1+an)

S9 = (9/2)*(2+26)

will help us find the sum of the first 9 terms of this arithmetic sequence

mario62 [17]2 years ago
3 0

Answer:

A. S9 = (9/2)*(2+26)


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A notary receives $ 3500 for elaborating a title property and $2000 for the constitutive act of an enterprise. In a month did a
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Answer:

6 titles and 16 acts were elaborated

Step-by-step explanation:

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3 years ago
Can someone please help me!!!
maksim [4K]

Answer:

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Step-by-step explanation:

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2 years ago
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Which equation would you use to solve the following situation?
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