Сократите дробь: (x^3-1)/(7x^2-5x-2).

Ответ:

\[7x² - 5x - 2 = 0\]

\[D = 25 + 56 = 81\]

\[x_{1} = \frac{5 + 9}{14} = 1;\ \ \ \ \]

\[x_{2} = \frac{5 - 9}{14} = - \frac{4}{14} = - \frac{2}{7}.\]

\[7x^{2} - 5x - 2 =\]

\[= 7 \cdot (x - 1)\left( x + \frac{2}{7} \right) =\]

\[= (x - 1)(7x + 2).\]