Answer:
1: The diver is 8 feet below sea level.
2: -20
3: -20 + 20 = 0
Step-by-step explanation:
1: This is determined by adding 4 to negative 12. -12 +4 = -8
2: You get this by subtracting 12 from negative 8. -8 - 12 = -20
3: This is done by adding 20 to negative 20. -20 + 20 = 0