Question

me pueden explicar por favor que no entiendo

Answer 1

${( {3}^{ - 1} + {4}^{ - 1} )}^{2} = \\ {( \frac{1}{3} + \frac{1}{4} )}^{2} = \\ {( \frac{4}{12} + \frac{3}{12} )}^{2} = \\ {( \frac{7}{12} )}^{2} = \\ \frac{49}{144}$