Question

Помогите пожалуйста !!!

Answer 1

1. Г
2. Г
3. А
4. Г
5. В
6. А
7. В
8. А
9.
$6x \times (2x + 1) = 5x + 1 \\ 12 {x}^{2} + 6x = 5x + 1 \\ 12 {x}^{2} + 6x - 5x - 1 = 0 \\ 12 {x}^{2} + x - 1 = 0 \\ x = \frac{ - 1 + - \sqrt{ {1}^{2} - 4 \times 12 \times ( - 1)} }{2 \times 12} \\ x = \frac{ - 1 + - \sqrt{1 + 48} }{24} \\ x = \frac{ - 1 + - \sqrt{49} }{24} \\ x = \frac{ - 1 + - 7}{24} \\ x = \frac{ - 1 + 7}{24} = \frac{1}{4} \\ x = \frac{ - 1 - 7}{24} = - \frac{1}{3}$
10.
${x}^{4} - 8 {x}^{2} - 9 = 0 \\ t {}^{2} - 8t - 9 = 0 \\ t = 9 \\ t = - 1 \\ {x}^{2} = 9 \\ {x}^{2} = - 1 \\ x = 3 \\ x = - 3$