Let's analyze each equation one by one to determine the number of solutions:
1. **Equation:** \( x - 7 = 7 - x \)
**Solving:**
- Rearranging gives: \( x + x = 7 + 7 \)
- This simplifies to: \( 2x = 14 \)
- Thus, \( x = 7 \)
**Number of solutions:** 1 solution
2. **Equation:** \( 3(x + 5) = 3x + 5 \)
**Solving:**
- Expanding the left side gives: \( 3x + 15 = 3x + 5 \)
- Subtracting \( 3x \) from both sides results in: \( 15 = 5 \)
- This statement is false.
**Number of solutions:** 0 solutions
3. **Equation:** \( 10 - x = 25 \)
**Solving:**
- Rearranging gives: \( -x = 25 - 10 \)
- Which simplifies to: \( -x = 15 \)
- Thus, \( x = -15 \)
**Number of solutions:** 1 solution
4. **Equation:** \( 2(x + 4) = 2x + 5 + 3 \)
**Solving:**
- Expanding the left side gives: \( 2x + 8 = 2x + 8 \)
- This results in a true statement (both sides are equal).
**Number of solutions:** Infinite solutions (the equation is true for all values of \( x \))
### Summary of Number of Solutions:
1. \( x - 7 = 7 - x \) → 1 solution
2. \( 3(x + 5) = 3x + 5 \) → 0 solutions
3. \( 10 - x = 25 \) → 1 solution
4. \( 2(x + 4) = 2x + 5 + 3 \) → Infinite solutions