Chapter 9 - Basic Algebra - 9.2 Adding and Subtracting Signed Numbers - 9.2 Exercises - Page 640: 12

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To add $-7+(-3)$, we can take the absolute value of both numbers. $|-7|=7$ $|-3|=3$ To add two negative numbers, we can add the absolute value of both numbers and then add a negative sign in front of the result. $|-7|+|-3|=7+3=10$ Therefore, $-7+(-3)=-10$.