To find the values of \( a \) and \( b \) using the provided arithmetic sequence formula \( a_n = -8 + (n-1) \cdot 2 \), we first need to determine the appropriate values of \( n \) for \( x = 2 \) and \( x = 4 \).
-
For \( x = 2 \): We can set \( n = 2 \) since it's the second term. \[ a_2 = -8 + (2-1) \cdot 2 = -8 + 1 \cdot 2 = -8 + 2 = -6 \] So, \( a = -6 \).
-
For \( x = 4 \): We set \( n = 4 \) since it's the fourth term. \[ a_4 = -8 + (4-1) \cdot 2 = -8 + 3 \cdot 2 = -8 + 6 = -2 \] So, \( b = -2 \).
From the calculations above, we find that:
- \( a = -6 \)
- \( b = -2 \)
The correct response is: a equals negative 6; b equals negative 2.