Giá trị của $B=\left(\sqrt{\frac{25}{4}}-1\right)^{3}+\left(\sqrt{\frac{9}{4}}-\frac{1}{2}\right)^{13}-\sqrt{\frac{49}{4}}$ là

$% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfKttLearuGlw5gvP1wzaeXatLxBI9gBam % XvP5wqSXMqHnxAJn0BKvguHDwzZbqegm0B1jxALjhiov2DaeHbuLwB % Lnhiov2DGi1BTfMBaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFf % euY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9 % q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGacaGaaeqaba % WaaqaafaaakqaabeqaaabaaaaaaaaapeGaemOqaiKaeyypa0ZaaeWa % a8aabaWdbmaalaaabaGaeGynaudabaGaeGOmaidaaiabgkHiTiabig % daXaGaayjkaiaawMcaa8aadaahaaWcbeqaa8qacqaIZaWmaaGccqGH % RaWkdaqadaWdaeaapeWaaSaaaeaacqaIZaWmaeaacqaIYaGmaaGaey % OeI0YaaSaaa8aabaWdbiabigdaXaWdaeaapeGaeGOmaidaaaGaayjk % aiaawMcaa8aadaahaaWcbeqaa8qacqaIXaqmcqaIZaWmaaGccqGHsi % sldaWcaaqaaiabiEda3aqaaiabisda0aaaaeaacqGH9aqpdaqadaqa % amaalaaabaGaeG4mamdabaGaeGOmaidaaaGaayjkaiaawMcaamaaCa % aaleqabaGaeG4mamdaaOGaey4kaSIaeGymaeZaaWbaaSqabeaacqaI % XaqmcqaIZaWmaaGccqGHsisldaWcaaqaaiabiEda3aqaaiabisda0a % aaaeaacqGH9aqpdaWcaaqaaiabiodaZmaaCaaaleqabaGaeGOmaida % aaGcbaGaeGOmaiZaaWbaaSqabeaacqaIYaGmaaaaaOGaey4kaSIaeG % ymaeJaeyOeI0YaaSaaaeaacqaI3aWnaeaacqaI0aanaaaabaGaeyyp % a0ZaaSaaaeaacqaI5aqoaeaacqaI0aanaaGaey4kaSIaeGymaeJaey % OeI0YaaSaaaeaacqaI3aWnaeaacqaI0aanaaaabaGaeyypa0ZaaSaa % aeaacqaIXaqmcqaIZaWmaeaacqaI0aanaaGaey4kaSYaaSaaaeaacq % aI3aWnaeaacqaI0aanaaGaeyypa0ZaaSaaaeaacqaIYaGmcqaIWaam % aeaacqaI0aanaaGaeyypa0JaeGynaudaaaa!7BEE! \begin{array}{l} B = {\left( {\frac{5}{2} - 1} \right)^3} + {\left( {\frac{3}{2} - \frac{1}{2}} \right)^{13}} - \frac{7}{4}\\ = {\left( {\frac{3}{2}} \right)^3} + {1^{13}} - \frac{7}{4}\\ = \frac{{{3^2}}}{{{2^2}}} + 1 - \frac{7}{4}\\ = \frac{9}{4} + 1 - \frac{7}{4}\\ = \frac{{13}}{4} + \frac{7}{4} = \frac{{20}}{4} = 5 \end{array}$