Question

Сократите дробь:
$\frac{a^{2} - 12a + 36 }{36-a^{2} }$

Answer 1

$\displaystyle\tt \frac{a^{2} - 12a + 36 }{36-a^{2} }=\frac{(6-a)^2}{(6-a)(6+a)}=\frac{6-a}{6+a}$

Answer 2

$\frac{a {}^{2} - 12a + 36 }{36 - a {}^{2} } \\ \\ \frac{(a - 6) {}^{2} }{(6 - a) \times (6 + a)} \\ \\ \frac{(a - 6) {}^{2} }{ - (a - 6) \times (6 + a)} \\ \\ \frac{ -( a - 6)}{6 + a} \\ \\ - \frac{a - 6}{6 + a} \\ \\ \frac{6 - a}{6 + a}$