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An arithmetic sequence is represented in the following table. Enter the

missing term of the sequence.
1 2 3 4 26
y -103 -94 -85 -76 ?​

1 Answer

3 votes

Answer:

122

Explanation:

An arithmetic sequence means a number is added each term. There is a term for where a number is multiplied as well. But in this case the first number is -103, the second number is -94 and the third number is -85. Can you tell what number is added each time?

The number is 9. -103+9=-94 and -94+9=-85 and so on. Now we want a way to find the term way further down the line.

Think of it doing it all at once. -103+9+9 gets us the third term right? so that's 2*9. -103+3*9 would get us the fourth. Hopefully that makes sense, but let me know if it doesn't. But for a few more examples, if we want the fifth term we would do -103+4*9 and getting the tenth would need -103+9*9. So basically we take the number term we want (in this case we want the 26th) and then take -103+ n*9, where n is the term we want minus 1, or in this case 25. so that's -103+25*9

Let me know if you need more of an explanation.

User Alex Kravchenko
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