Question

Решите плиз у меня экзамен

Answer 1

$\frac{ x^{2} -7x}{x-4}- \frac{12}{4-x} =0$
$\frac{ x^{2} -7x}{x-4} + \frac{12}{x-4}=0$
$\frac{ x^{2} -7x+12}{x-4} =0$
x² - 7x + 12 = 0                                                  x - 4 ≠ 0
D = 49 - 4 * 12 = 49 - 48 = 1                              x ≠ 4
$X _{1} = \frac{7- \sqrt{1} }{2} = \frac{7-1}{2} =3$
$X _{2}= \frac{7+ \sqrt{1} }{2} = \frac{7+1}{2} =4$ - не уд
Ответ: 3