If a is the predecessor of b, then the value of (a - b) and (b - a) are:

Options

A. `-1 and 1`
B. `1 and -1`
C. 0 and 1
D. 1 and 0

Answer

To solve the question, we need to understand the relationship between the numbers \( a \) and \( b \). Given that \( a \) is the predecessor of \( b \), it means that \( b \) is the next number after \( a \).

### Step-by-Step Solution:

1. **Understanding Predecessor and Successor**:
- If \( a \) is the predecessor of \( b \), then we can express this relationship as:
\[ b = a + 1 \]

2. **Calculate \( a - b \)**:
- We can substitute \( b \) in the expression \( a - b \):
\[ a - b = a - (a + 1) \]
- Simplifying this gives:
\[ a - b = a - a - 1 = -1 \]

3. **Calculate \( b - a \)**:
- Now, we will calculate \( b - a \) using the same substitution:
\[ b - a = (a + 1) - a \]
- Simplifying this gives:
\[ b - a = a + 1 - a = 1 \]

4. **Final Values**:
- Therefore, we find:
\[ a - b = -1 \]
\[ b - a = 1 \]

### Conclusion:
The values of \( (a - b) \) and \( (b - a) \) are:
- \( a - b = -1 \)
- \( b - a = 1 \)