In Exercises 1–6, write the first four terms of each sequence who...

Question

In Exercises 1–6, write the first four terms of each sequence whose general term is given. a_n = 7n - 4

Accepted Answer

Hello. Today we're gonna be figuring out what the first four terms of a given sequence is. So the given sequence is a sub N equal to four. N plus five. So when we're looking for a sub one, a sub two, A sub three and a sub four. We're allowing N to equal the sub scripts in each case. So for example if we're looking for a sub one we're allowing N two equal to one for this case. So doing that a sub one is going to equal to four times one plus five and four times one is just four. So we left with four plus five which is equal to nine. So a sub one is equal to nine. And we're gonna go ahead and repeat this process for a sub two. Sub three and a sub four. So looking for a sub two A sub two is equal to four times two plus 54 times two is eight. And we are left with eight plus five and eight plus five is equal to 13. So a sub two is equal to 13. Looking for a sub three ASAP three is gonna equal to four times three plus 54 times three is going to be 12. And we are left with 12 plus five which is equal to 17. So a sub three is equal to 17. And finally looking for a sub four ASAP four is going to be four times four plus five, four times 4, 16. So we're left with 16 plus five which is equal to 21. So a sub four is going to be 21 this is going to be the first four terms of this sequence. And that also means that the answer to this problem is going to be C. So I hope this video helps you in understanding how to find the first four terms of a sequence, and I'll go ahead and see you all in the next video.

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