Which of the following is true about -9

-9 is a negative number.

There are several possible interpretations and statements that can be true about the number -9:

1. -9 is a negative number: This is true because the number is less than zero.

2. -9 is an integer: This is true because -9 is a whole number that is not a fraction or a decimal.

3. -9 is odd: This is true because -9 cannot be divided evenly by 2.

4. -9 is less than -1: This is true because -9 is to the left of -1 on the number line.

5. -9 is greater than -10: This is true because -9 is to the right of -10 on the number line.

6. -9 is a multiple of 9: This is true because -9 can be obtained by multiplying 9 by -1.

7. -9 is a solution to the equation x + 9 = 0: This is true because when -9 is substitued for x in the equation, -9 + 9 equals 0.