Answer:
1. A, (+) + (-)
2. D, (+) + (+)
3. B, (-) + (-)
4. C, (-) + (+)
Step-by-step explanation:
1. When a positive number is subtracted from a positive, it becomes an added negative number. For example, 6 - 6 = 6 + (-6) = 0.
2. When a negative number is subtracted from a positive, it becomes an added positive number. In other words, subtracting a negative becomes adding a positive. For example, 6 - (-6) = 6 + 6 = 12.
3. When a negative number is added to a negative, it becomes a subtracted positive number. For example, -6 + (-6) = -6 - 6 = - 12.
4. When a negative number is subtracted from a negative, it becomes an added positive number. For example, -6 - (-6) = -6 + 6 = 0.
