Question

1. 27, 23, 19, 15, ...

Explanation:

Step1: Identify common difference

$d = 23 - 27 = -4$

Step2: Define nth term formula

For arithmetic sequence: $a_n = a_1 + (n-1)d$

Step3: Substitute known values

$a_n = 27 + (n-1)(-4) = 31 - 4n$

Step4: Find next term (n=5)

$a_5 = 31 - 4(5) = 31 - 20$

Answer:

The next term in the sequence is 11, and the nth term formula is $a_n = 31 - 4n$