В) 2a/(a² − 9) − 1/(a + 3)

Question

$a^{2} - 9 = (a - 3) (a + 3)$ .

$\frac{2 a - (a - 3)}{(a - 3) (a + 3)} = \frac{a + 3}{(a - 3) (a + 3)} = \frac{1}{a - 3}$ .

ОДЗ: $a \neq \pm 3$ .

Ответ: 1/(a − 3).

Accepted Answer

$a^{2} - 9 = (a - 3) (a + 3)$ .

$\frac{2 a - (a - 3)}{(a - 3) (a + 3)} = \frac{a + 3}{(a - 3) (a + 3)} = \frac{1}{a - 3}$ .

ОДЗ: $a \neq \pm 3$ .

Ответ: 1/(a − 3).