Question

Помогите решить номера.

Answer 1

Объяснение:

1. а)

$\frac{ {x}^{2} }{ {x}^{2} - 9} = \frac{12 - x}{ {x}^{2} - 9} \\ {x}^{2} = 12 - x \\ {x}^{2} - 12 - x = 0 \\ {x}^{2} + 4x - 3x - 12 = 0 \\ (x - 4) \times (x - 3) = 0 \\ x = - 4 \\ x = 3$

б)

$\frac{6}{x - 2} + \frac{5}{x} = 3 \\ \frac{6x + 5(x - 2) - 3x \times (x - 2}{x \times (x - 2)} = 0 \\ \frac{17x - 10 - {3x}^{2} }{x \times (x - 2)} = 0 \\ 17x - 10 - {3x}^{2} = 0 \\ {3x}^{2} - 2x - 15x + 10 = 0 \\ (3x - 2) \times (x - 5) = 0 \\ x = \frac{2}{3} \\ x = 5$

2.а)

${4}^{2} = 16$

б)

${6}^{ - 2} = \frac{1}{ {6}^{2} } = \frac{1}{36}$

в)

${2}^{ - 6} = \frac{1}{64}$

3.а)

${x}^{ - 12} \times {x}^{14} = {x}^{2}$

б)

$6 {a}^{ - 1} b = 6 \times \frac{1}{a} \times b = \frac{6b}{a}$

5.

$\frac{ {3}^{ - 9} \times {3}^{ - 8} }{ {3}^{ - 18} } = {3}^{9} \times {3}^{ - 8} = 3$