Question

$\frac{a}{a+b} - \frac{b}{a-b}$

Answer 1

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