Find the fifth term of an=2 (-1) n

The 5th answer in this series would be - 2.

We know this because in any problem where we have a base (2) being multiplied by a - 1^n power, the numbers will simply alternate between positive 2 and negative 2. All of the even powers will be positive 2 and all of the odd numbers will be negative 2. See the work below.

2 (-1) (-1) (-1) (-1) (-1)

2 (1) (-1) (-1) (-1)

2 (1) (1) (-1)

2 (-1)

-2

So since 5 is odd, the answer is negative 2.