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LilyMQ
 one year ago
Identify the 35th term of an arithmetic sequence where a1 = 7 and a18 = 95.
LilyMQ
 one year ago
Identify the 35th term of an arithmetic sequence where a1 = 7 and a18 = 95.

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LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0a. 203 b. 197 c. 168 d. 163

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2Define what an arithmetic sequence is first. Do you know general form?

LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0I have no idea what any of this is lol

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2Alright, so an arithmetic sequence is defined by the general form: \[\large a_n = a_1 + (n1)d\]

LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0how can I calculate the common difference?

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2@aric200 no need to criticize.

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2n = the number of terms you're looking for in the sequence d = difference between the terms (preceding number  previous number) \(a_1\) = the first value in the sequence of numbers.

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2So if we have \(a_{\color{red}n} = a_{\color{red}{18}}\) what does that tell you about the number of terms in the sequence?

aric200
 one year ago
Best ResponseYou've already chosen the best response.1I'm simply trying to say your teacher more than likely gave you background on what you are doing in less this is a pretest in which you should not even be asking for our help, but If not then I'm sure there is text that pertains to this type of math and going back over that could help you get a better understanding. Thats the best thing to do when you "have any idea what this is"

aric200
 one year ago
Best ResponseYou've already chosen the best response.1That is all but continue with your explanation.

LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0@Jhannybean does that mean you are trying to find the 18th term?

aric200
 one year ago
Best ResponseYou've already chosen the best response.1She gave you the formula an = a1 + (n – 1)d

LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0I got a(31)=38+(311) but I'm not sure how to find d

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2We are given \(\large a_{18} = a_n = 95\) That means if we take a closer look at this relation, we see that \(n=18\)

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2This is basically telling us that if we had a 18 numbers in a sequence, our value of \(a_n\) would be 95.

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2So far we have :\[95 =7+(18  1)d\] Are you following?

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2Now can you solve d for me?

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2Yes, so \(d=6\). Now we're trying to find the 35th term in the sequence, this means we are trying to find \(a_n\) when \(n=35\)

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2Now that we've found \(d=6\), it should be easy :)

LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0I got 197 for the answer. Is this correct?

LilyMQ
 one year ago
Best ResponseYou've already chosen the best response.0YAY! Thank you so much!

aric200
 one year ago
Best ResponseYou've already chosen the best response.1Here it is all together for you and anyone else who stumbles upon this question later. Makes it less complicated in my opinion but good job. x(n)=a+d(n1) 95=7+d(181) 95=7+d(17) 95+7=d(17) 102=17d d=102/17 d=6 After finding D plug it in x(35)=7+6(351) x(35)=7+6(34) x(35)=7+204 x(35)=197 So the answer is B) 197

Jhannybean
 one year ago
Best ResponseYou've already chosen the best response.2\[a_n= 7 +(351)(6)\]\[a_n=7+204\]\[a_n = 197~ \checkmark \]
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