Question

2x^2+xКорень5-15=0



(Между x и 5 корень)

Answer 1

Ответ:

$2x^2 + x\sqrt{5} - 15 = 0\\\\D = 5 + 120 = 125\\\\\sqrt D = 5\sqrt{5}\\\\ x_1=\frac{-\sqrt{5}-5\sqrt 5}{4} = -\frac{6\sqrt 5}{4} = -1,5\sqrt 5\\\\x_2=\frac{-\sqrt{5}+5\sqrt 5}{4} = \frac{4\sqrt 5}{4} = \sqrt 5$