Question

Допоможіть даю 30 балів...

Answer 1

Ответ:

Добрый вечер, смотрите ответ в фото.

Answer 2

Ответ:

№1

а) 3x² - 18 = 0

3x² = 18

x² = 6

x = ±√6

б) 3x² - 24x = 0

3x(x - 8) = 0

3x = 0

x = 0

x - 8 = 0

x = 8

в) 12y² + y - 6 = 0

D = 1 + 288 = 289

y1 =

$\frac{ - 1 + \sqrt{289} }{12 \times 2} = \frac{ - 1 + 17}{24} = \frac{16}{24} = \frac{2}{3}$

y2 =

$\frac{ - 1 - 17}{24} = \frac{ - 18}{24} = - \frac{3}{4}$

г) y² - 14y + 40 = 0

{y1 + y2 = 14 {y1 = 4

{y1 · y2 = 40 {y2 = 10

д) 7x² - x - 8 = 0

D = 1 + 224 = 225

x1 =

$\frac{1 + \sqrt{225} }{7 \times 2} = \frac{1 + 15}{14} = \frac{16}{14} = \frac{8}{7} = 1 \frac{1}{7}$

x2 =

$\frac{1 - 15}{14} = \frac{ - 14}{14} = - 1$

№2

{x1 + x2 = -b

{x1 · x2 = c

{-8 + 3 = -5

{-8 · 3 = -24

b = 5; c = -24

x² + 5x - 24 = 0