Question

2х во 2 степени+3х-1=0

Answer 1

Решение и ответ:

$\displaystyle 2{x^2}+3x-1=0$

$\displaystyle D={b^2}-4ac={3^2}-4\cdot2\cdot (-1)=9+8=17$

$\displaystyle x=\frac{{-b\pm\sqrt D}}{{2a}}=\frac{{-3\pm\sqrt {17}}}{{2\cdot 2}}=\frac{{-3\pm\sqrt {17}}}{4}$

$\displaystyle \boxed{{x_1}=\frac{{-3+\sqrt{17}}}{4}}$

$\displaystyle \boxed{{x_2}=\frac{{-3-\sqrt{17}}}{4}}$