\(
\eqalign{
& x^2 - 5x + 2\frac{3}
{4} = 0 \cr
& 4x^2 - 20x + 11 = 0 \cr
& \left( {2x - 5} \right)^2 - 25 + 11 = 0 \cr
& (2x - 5)^2 - 14 = 0 \cr
& 2x - 5 = \pm \sqrt {14} \cr
& x = 2\frac{1}
{2} - \sqrt {14} \vee x = 2\frac{1}
{2} + \sqrt {14} \cr}
\)
