To find the missing values \( a \) and \( b \) in the table using the arithmetic sequence formula \( a_n = -8 + (n-1) \cdot 2 \), we need to determine the values of \( n \) corresponding to \( x = 2 \) and \( x = 4 \).
-
Finding \( a \) when \( x = 2 \):
- We need to find \( n \) such that \( x = 2 \).
- Since the first term corresponds to \( n=1 \), let’s substitute \( n = 1 \): \[ a_1 = -8 + (1 - 1) \cdot 2 = -8 + 0 = -8 \]
- Thus, \( a \) corresponds to \( n = 1 \), and since \( x=2 \) corresponds to \( n=1 \), we find: \[ a = -8 \]
-
Finding \( b \) when \( x = 4 \):
- Next, we find \( n \) such that \( x = 4 \). Observe that if \( x \) increases by 2, we assume that \( n \) increases by 1.
- Hence, we set \( n = 2 \): \[ a_2 = -8 + (2 - 1) \cdot 2 = -8 + 2 = -6 \]
- So, \( b \) corresponds to \( n = 2 \), and since \( x=4 \), we find: \[ b = -6 \]
Putting this all together:
- \( a = -8 \)
- \( b = -6 \)
Since none of the provided answer options directly match \( a = -8 \) and \( b = -6 \), based on the options you've presented, you may want to recheck if there was a mistake in the problem or options.
For the context of your question:
- If we reconsider if we missed anything, here's the summary to validate:
- With \( n = 1 \) for \( x=2, ; a = -8 \)
- With \( n = 2 \) for \( x=4, ; b = -6 \)
Would you like to adjust or proceed further?