1. The problem is to find the result of subtracting 9 from 18, both integers. 2. The subtraction formula is $a - b = c$, where $a$ and $b$ are integers and $c$ is the result. 3. Substitute the values: $18 - 9 = c$. 4. Perform the subtraction: $18 - 9 = 9$. 5. Therefore, the answer is $9$.