Question

решите уравнение 3x²+5х=2-2х-х²

Answer 1

$({3 x}^{2} + {x}^{2} ) +( {5x} + 2x ) - 2 = \\ = 0 \\ {4x}^{2} + {7x } - 2 = 0$
D=${b}^{2} - 4ac$
D= 49-4*4*(-2) =49+32=81=9^2
$x1 = \frac{ - b + \sqrt{d} }{2a} \\ x1 = \frac{ - 7 + 9}{8} \\ x1 = \frac{2}{8} = \frac{1}{4}$
$x2 = \frac{ - b - \sqrt{d} }{2a} \\ x2 = \frac{ - 7 - 9}{8} \\ x2 = \frac{ - 16}{8} = - 2$
Ответ: 0.25;-2