Without additional context or criteria to determine the correct equation, we cannot select an answer. However, if we assume the task is to simply list the equations, they are:
- \(\boxed{x = -\frac{3}{4} A - \frac{1}{2} b + \frac{5}{2}}\)
- \(\boxed{x = \frac{1}{2} A + \frac{3}{4} b + \frac{5}{2}}\)
- \(\boxed{x = -\frac{1}{2} A - \frac{3}{4} b + \frac{5}{2}}\)