Explanation

To find the missing operator, let's look at the sequence:

4 _ 9 _ 6 _ 18 _ 7 = -16

From the pattern, it seems that the first number is being operated upon with the second number to produce the third number, and then the fourth number is operated upon with the fifth number to produce the sixth number.

4 _ 9 _ 6 _ 18 _ 7 = -16

Given that the sequence results in a negative number, it's likely that subtraction is involved.

Let's check:

4 - 9 = -5

6 - 18 = -12

7 - (-16) = 7 + 16 = 23

So, the sequence becomes:

4 - 9 ÷ 6 - 18 × 7 = -16