Question

\frac{a}{a-5}-\frac{a^2}{a^2-10a+25}

Answer 1

$\frac{a}{a-5}-\frac{a^2}{a^2-10a+25} = \\ = \frac{a}{a-5}-\frac{a^2}{(a - 5)^2} = \frac{a(a - 5) - {a}^{2} }{(a - 5)^2} = \\ = \frac{ {a}^{2} - 5a - {a}^{2} }{ {(a - 5)}^{2} } = \frac{ - 5a }{ {(a - 5)}^{2} }$