\[\left(\frac{13}{2}\right)^2 - 4\left(\frac{13}{2}\right) + 4 - \left(\frac{13}{2} - 3\right)^2\]
\[\frac{169}{4} - \frac{52}{2} + 4 - \left(\frac{13}{2} - \frac{6}{2}\right)^2\]
\[\frac{169}{4} - \frac{104}{4} + \frac{16}{4} - \left(\frac{7}{2}\right)^2\]
\[\frac{169}{4} - \frac{104}{4} + \frac{16}{4} - \frac{49}{4}\]
\[\frac{169 - 104 + 16 - 49}{4}\]
\[\frac{32}{4}\]
\[8\]
Ответ: 8