$$\left. \begin{array} { l } { A = ( 2 x + 3 ) ^ { 3 } \quad B = ( x - 2 ) ^ { 3 } } \\ { C = ( 1 - \sqrt { 2 } ) ( 1 + \sqrt { 2 } ) + ( 1 + \sqrt { 2 } ) \right.$$
