Question

решите уравнение: 3x - 2√x - 8 = 0

Answer 1

$3x - 2\sqrt{x}-8 = 0\\\\ \sqrt{x} = t\\\\ t > 0\\\\ 3t^2-2t-8 = 0\\\\ t_1t_2 = -\frac{8}{3} = -\frac{4}{3}*2\\\\ t_1+t_2 = \frac{2}{3} = \frac{6}{3} - \frac{4}{3} = 2 - \frac{4}{3}\\\\ t_1 = -\frac{4}{3}\\\\ t_2 = 2\\\\ \sqrt{x} = 2\\\\ \fbox{x = 4}$