The sum of $-3 + (-7)$ is $-10$.

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Here are 5 related questions:

1. What is the sum of $-5 + (-8)$?
2. How do you add two negative numbers?
3. What is the difference between $-10$ and $5$?
4. What is the sum of $3 + (-7)$?
5. How do you subtract a negative number from another negative number?

Tip: When adding two negative numbers, the result is always negative.