Question

$\frac{7 x^{2} - x}{7 x^{2}+13x-2 }$
СОКРАТИТЕ ПОЖАЛУЙСТА

Answer 1

Раскладываем на множители 7x^2 + 13x - 2 ....
7x^2 + 13x - 2 = 0
D = 13^2 - 4*7(-2) = 169 +56 = 225
√225 = 15
x_1 = (-13+15)/14 = 2/14 = 1/7
x_2 = (-13-15)/14 = -28/14 = -2
7x^2 + 13x - 2 = 7*(x - 1/7)(x + 2) = (7x - 1)(x + 2)
$\\\frac{7x^2 - x}{7x^2+13x-2}=\frac{x(7x-1)}{(7x-1)(x+2)}=\frac{x}{x+2}$