Question

Очень срочно!!!
!!!!

Answer 1

Ответ:

1.    $\frac{m}{n} - \frac{n}{m} = \frac{m^{2} - n^{2}}{mn}$

2.   $\frac{x^{2} - 49}{6x + 42} = \frac{x^{2} - 7^{2}}{6(x + 7)} = \frac{(x-7)(x+7)}{6(x+7)} = \frac{x-7}{6}$

3.   $\frac{24m}{n^{3}} : (6m^{2}n )= \frac{24m}{n^{3} * 6m^{2}n } = \frac{24m}{6n^{4}m^{2}} = \frac{4}{n^{4}m}$

4.   (7 - √3)(7 + √3) = 7² - √3² = 49 - 3 = 46

5.  

  3x² - 7x + 2 = 0

  D = (-7)² - 4 *2 * 3 = 49 - 24 = 25

  $x_{1} = \frac{-b + \sqrt{D} }{2a} = \frac{7 + 5}{6} = \frac{12}{6} = 2\\\\x_{2} = \frac{-b - \sqrt{D} }{2a} = \frac{7 - 5}{6} = \frac{2}{6} = \frac{2}{3}$