Question

А, Б и В. Задание на скрине.

Answer 1

а) 14х² - 9х = 0

х(14х - 9) = 0

х1 = 0 или 14х - 9 = 0

14х = 9

х = 9/14

Ответ: 0; 9/14

б) 2х² - 11х + 12 = 0

D = b² - 4ac = (-11)² - 4 × 2 × 12 = 121 - 96 = 25

$\sqrt{d} = \sqrt{25} = 5$

$x1 = \frac{ - b - \sqrt{d} }{2a} = \frac{11 - 5}{2 \times 2} = \frac{6}{4} = 1.5 \\ \\ x2 = \frac{ - b + \sqrt{d} }{2a} = \frac{11 + 5}{2 \times 2} = \frac{16}{4} = 4$

Ответ: 1,5; 4

в)

16х² = 49

х² = 49 ÷ 16

${x}^{2} = \frac{49}{16} \\ \\ x = \sqrt{ \frac{49}{16} } \\ \\ x = \frac{7}{4} \\ \\ x = - \frac{7}{4}$

Ответ: 7/4; - 7/4