Answer:
-2
Step-by-step explanation:
You multiply each term by -2 to get the next term.
To find this for this sequence, divide the term on the right by the term on the left.
8 / -4 = -2 or -4 * -2 = 8
-16 / 8 = -2 or 8 * -2 = -16
32 / -16 = -2 or -16 * -2 = 32
-64 / 32 = -2 or 32 * -2 = -64
