Сократить дробь: (2x^2+5x-3)/(x^2-9).

Question

Вопрос:

Ответ:

Accepted Answer

$\frac{2 x^{2} + 5 x - 3}{x^{2} - 9} =$

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

$2 x^{2} + 5 x - 3 =$

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

$= (2 x - 1) (x + 3)$

$D = 25 + 24 = 49$

$x_{1} = \frac{- 5 + 7}{4} = \frac{1}{2};$

$x_{2} = \frac{- 5 - 7}{4} = - 3.$