7.

Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

A(n) = –3 + (n – 1)(–2.2)

1 answer

To find the terms of the arithmetic sequence given by the formula \( A(n) = -3 + (n - 1)(-2.2) \), we can substitute \( n \) with the desired term numbers.

  1. First term \( A(1) \): \[ A(1) = -3 + (1 - 1)(-2.2) = -3 + 0 \cdot (-2.2) = -3 \]

  2. Fourth term \( A(4) \): \[ A(4) = -3 + (4 - 1)(-2.2) = -3 + 3 \cdot (-2.2) = -3 - 6.6 = -9.6 \]

  3. Tenth term \( A(10) \): \[ A(10) = -3 + (10 - 1)(-2.2) = -3 + 9 \cdot (-2.2) = -3 - 19.8 = -22.8 \]

Now we have the first, fourth, and tenth terms of the sequence:

  • First term \( A(1) = -3 \)
  • Fourth term \( A(4) = -9.6 \)
  • Tenth term \( A(10) = -22.8 \)