Question

can anyone solved this for me?

Answer 1

$rhs \\ \\ \frac{ {a}^{ - 1} }{ {a}^{ - 1} + {b}^{ - 1} } + \frac{ {a}^{ - 1} }{ {a}^{ - 1} - {b}^{ - 1 } } \\ \\ = \frac{ {a}^{ - 1}( {a}^{ - 1} - {b}^{ - 1} ) + {a}^{ - 1} ( {a}^{ - 1} + {b}^{ - 1} )}{{a}^{ - 2} - {b}^{ - 2} } \\ \\ = \frac{ {a}^{ - 1} ( {2a}^{ - 1} )}{ \frac{1}{ {a}^{2} } - \frac{1}{ {b}^{2} } } \\ \\ = \frac{2 {a}^{ - 2} }{ \frac{ {b}^{2} - {a}^{2} }{ {a}^{2} {b}^{2} } } \\ \\ = \frac{2 {a}^{2} {b}^{2} }{ {a}^{2} ( {b}^{2} - {a}^{2}) } \\ \\ = \frac{2 {b}^{2} }{ {b}^{2} - {a}^{2} }$