1. The problem asks us to calculate $7 + (-9)$. 2. Adding a negative number is the same as subtracting the positive value of that number. So, $7 + (-9)$ is the same as $7 - 9$. 3. Calculate $7 - 9$: since 9 is greater than 7, the result will be negative. 4. Subtract 7 from 9: $9 - 7 = 2$. 5. Since 9 was larger and we are subtracting it from 7, the answer is $-2$. Final answer: $7 + (-9) = -2$