Question

помогите пожалуйста.....​

Answer 1

Объяснение:

3.

x≠-2;x≠1

$\frac{x}{x + 2} = \frac{2}{x - 1} \\ x(x - 1) = 2(x + 2) \\ x {}^{2} - x = 2x + 4 \\ x {}^{2} - 3x - 4 = 0 \\ D = 9 - 4 \times - 4 = 9 + 16 = 25 \\ x1 = \frac{3 - 5}{2} = \frac{ - 2}{2} = - 1 \\ x2 = \frac{3 + 5}{2} = \frac{8}{2} = 4$

4.

$\frac{x {}^{2} - 2x}{2x {}^{2} - 10x + 12 } = \frac{x(x - 2)}{2(x - 2)(x - 3)} = \frac{x}{2x - 6}$

5.

$x {}^{2} - 3 |x| - 4 = 0$

1)

$x {}^{2} - 3x - 4 = 0 \\D = 25 \\ x1 = \frac{3 - 5}{2} = - 1 \\ x2 = \frac{3 + 5}{2} = 4$

x≥0;x=4.

2)

$x {}^{2} - 3 \times - x - 4 = 0 \\ x {}^{2} + 3x - 4 = 0 \\ D = 25 \\ x1 = \frac{ - 3 - 5}{2} = - 4 \\ x2 = \frac{ - 3 + 5}{2} = 1$

x≤0;x=-4.