Question

$\frac{3}{x} - \frac{12}{x - 3} = 1$
решите пж​

Answer 1

$\frac{3}{x} - \frac{12}{x - 3} = 1 \: \: \: \: \: | \: x \ne3\\ \frac{x}{3} - \frac{12}{x - 3} - 1 = 0 \\ \frac{x(x - 3) - 36 - 3(x - 3)}{3(x - 3)} = 0 \\ \frac{ {x}^{2} - 3x - 36 - 3x + 9 }{3(x - 3)} = 0 \\ \frac{ {x}^{2} - 6x - 27 }{3(x - 3)} = 0 \\ {x}^{2} - 6x - 27 = 0 \\ {x}^{2} + 3x - 9x - 27 = 0 \\ x(x + 3) - 9(x + 3) = 0 \\ (x + 3)(x - 9) = 0 \\ x + 3 = 0 \\ \bold{x_1 = - 3} \\ x - 9 = 0 \\ \bold{x_2 = 9}$