Final answer:
The pattern in the given sequence is that each term is obtained by multiplying the previous term by -2. The expression for the pattern is (-2)^(n-1).
Step-by-step explanation:
The pattern in the given sequence is that each term is obtained by multiplying the previous term by -2. Let's examine the pattern:
First term: -2
Second term: (-2) x (-2) = 4
Third term: 4 x (-2) = -8
Fourth term: -8 x (-2) = 16
So, the expression for the pattern is:
nth term = (-2)n-1