(a) Simplify : \(\frac{3\frac{1}{12} + \frac{7}{8}}{2\frac{1}{4} - \frac{1}{6}}\)
(b) If \(p = \frac{m}{2} - \frac{n^{2}}{5m}\) ;
(i) make n the subject of the relation ; (ii) find, correct to three significant figures, the value of n when p = 14 and m = -8.
Show Answer Show Explanation Explanation (a) \(\frac{3\frac{1}{12} + \frac{7}{8}}{2\frac{1}{4} - \frac{1}{6}}\) \(3\frac{1}{12} + \frac{7}{8} = \frac{37}{12} + \frac{7}{8}\) = \(\frac{74 + 21}{24}\) = \(\frac{95}{24}\) \(2\frac{1}{4} - \frac{1}{6} = \frac{9}{4} - \frac{1}{6}\) = \(\frac{27 - 2}{12}\) = \(\frac{25}{12}\) \(\therefore \frac{3\frac{1}{12} + \frac{7}{8}}{2\frac{1}{4} - \frac{1}{6}} = \frac{95}{24} \div \frac{25}{12}\) \(\frac{95}{24} \times \frac{12}{25} = \frac{19}{10}\) = \(1.9\) (b)(i) \(p = \frac{m}{2} - \frac{n^{2}}{5m}\) \(\frac{n^{2}}{5m} = \frac{m}{2} - p\) \(n^{2} = 5m(\frac{m}{2} - p)\) \(n = \pm \sqrt{5m(\frac{m}{2} - p)}\) (ii) When p = 14 and m = -8, \(n = \sqrt{5(-8)(\frac{-8}{2} - 14)}\) \(n = \sqrt{-40(- 4 - 14)}\) \(n = \sqrt{720}\) \(n = 12\sqrt{5}\) = \(\pm 26.83\)