The sum of two integers is -11. If one of them is 9, find the other.

Options

A. `-30`
B. `-20`
C. `-40`
D. `-10`

Answer

To solve the problem step by step, we will follow these instructions:

1. **Understand the problem**: We know that the sum of two integers is -11, and one of the integers is 9. We need to find the other integer.

2. **Set up the equation**: Let the second integer be represented as \( x \). According to the problem, we can write the equation:
\[ 9 + x = -11 \]

3. **Isolate the variable**: To find \( x \), we need to isolate it on one side of the equation. We can do this by subtracting 9 from both sides:
\[ x = -11 - 9 \]

4. **Perform the calculation**: Now we will calculate the right side:
\[ x = -20 \]

5. **Conclusion**: The other integer is \( -20 \).

### Final Answer:
The other integer is \( -20 \).