finish the arithmetic sequence -23,__,__,__,__,__,__,5

1 answer

To find the missing terms in the arithmetic sequence \(-23, __, __, __, __, __, __, 5\), we first need to determine the common difference \(d\).

The first term \(a_1\) is \(-23\), and the last term \(a_8\) is \(5\). The sequence has 8 terms, so the \(n\)-th term of an arithmetic sequence can be expressed as:

\[ a_n = a_1 + (n - 1)d \]

For the 8th term (\(n = 8\)):

\[ a_8 = a_1 + (8 - 1)d \] \[ 5 = -23 + 7d \]

Now we solve for \(d\):

\[ 5 + 23 = 7d \] \[ 28 = 7d \] \[ d = \frac{28}{7} = 4 \]

Now that we have the common difference \(d = 4\), we can find the missing terms:

  1. \(a_2 = a_1 + d = -23 + 4 = -19\)
  2. \(a_3 = a_2 + d = -19 + 4 = -15\)
  3. \(a_4 = a_3 + d = -15 + 4 = -11\)
  4. \(a_5 = a_4 + d = -11 + 4 = -7\)
  5. \(a_6 = a_5 + d = -7 + 4 = -3\)
  6. \(a_7 = a_6 + d = -3 + 4 = 1\)

Therefore, the completed arithmetic sequence is:

\(-23, -19, -15, -11, -7, -3, 1, 5\)