\fraca + \frac12 \cdot \frac2a\sqrt73a - \frac32 \cdot \frac2a\sqrt73 = \fraca + \fraca\sqrt73a - a\sqrt7 = \frac1 + \frac\sqrt731 - \sqrt7 = \frac\frac3 + \sqrt731 - \sqrt7 = \frac3 + \sqrt73(1 - \sqrt7). - go-checkin.com