Question

Решите целое уравнение
(х²+3х)(х²+3х-2)=3

Answer 1

$( {x}^{2} + 3x)( {x}^{2} + 3x - 2 ) = 3 \\ {x}^{2} + 3x = t \\ t(t - 2) = 3 \\ {t}^{2} - 2t - 3 = 0 \\ \frac{d}{4} = 1 + 3 = 4 \\ t = 1 + 2 = 3 \\ t = 1 - 2 = - 1 \\ {x}^{2} + 3x = 3 \\ {x}^{2} + 3x - 3 = 0 \\ d = 9 + 12 = 21 \\ x = \frac{ - 3 + \sqrt{21} }{2} \\ x = \frac{ - 3 - \sqrt{21} }{2 } \\ {x }^{2} + 3x = - 1 \\ {x}^{2} + 3x + 1 = 0 \\ d = 9 - 4 = \sqrt{5} \\ x = \frac{ - 3 + \sqrt{5} }{2} \\ x = \frac{ - 3 - \sqrt{5} }{2}$