Let's analyze each equation one by one to determine the number of solutions:
A. \( x - 7 = 7 - x \)
Combine like terms: \[ x + x = 7 + 7 \] \[ 2x = 14 \] \[ x = 7 \]
This equation has one solution.
B. \( 3(x + 5) = 3x + 5 \)
Expand the left side: \[ 3x + 15 = 3x + 5 \]
Subtract \( 3x \) from both sides: \[ 15 = 5 \]
This is a false statement, indicating that there is no solution. So this equation has no solutions.
C. \( 10 - x = 25 \)
Rearranging gives: \[ -x = 25 - 10 \] \[ -x = 15 \] \[ x = -15 \]
This equation has one solution.
D. \( 2(x + 4) = 2x + 5 + 3 \)
Expand the left side: \[ 2x + 8 = 2x + 8 \]
Subtract \( 2x \) from both sides: \[ 8 = 8 \]
This is a true statement for all values of \( x \). Therefore, this equation has infinitely many solutions.
To summarize:
- A: One solution
- B: No solutions
- C: One solution
- D: Infinitely many solutions