Answer:
1. 13
2. 16
3. 27
4. 0
5. 2
Step-by-step explanation:
1. 6-(-7) becomes 6+7 because subtracting a negative number is the same as adding that positive number
2. simple, add 15+9 and then subtract 8
3. the same thing as #1, 18-(-9) becomes 18+9
4. 3+(-3) becomes 3-3 because adding a negative number is the same as subtracting the number
5. may be simpler if you reorder the equation in your head like "4-2"
