Question

The general formula for a sequence is f(x)=3x-7f(x)=3x−7 . One terms in the sequence is 8. Which term is this? The th term is 8.

Answer 1

What does this problem ask for:

--> position of '8' in the sequence

Since our general formula: f(x) = 3x - 7

--> 'x' represents the position of the term in the sequence

--> f(x) is the term in the sequence

--> therefore, if we plug '8' into f(x)

--> we can find 'x' which is the position of 8 in the sequence

Thus:

`8=3x-7\\3x=8+7\\3x=15\\x=5`

8 is the 5th term

Answer: 5th term

Answer 2

Explanation:

If the arithmetic sequence is f(x) = 3x-7, x stands for the position of the number in the sequence. In other words, we are looking to solve for x when f(x) = 8:

8 = 3x - 7 and

15 = 3x so

x = 5. The position of the number 8 is the 5th position.