Найдите корни уравнения: -x(4x+1)=(x+2)(x-2).

\[- x(4x + 1) = (x + 2)(x - 2)\]

\[- 4x^{2} - x = x^{2} - 4\]

\[x^{2} - 4 + 4x^{2} + x = 0\]

\[5x² + x - 4 = 0\ \]

\[D = b^{2} - 4ac =\]

\[= 1 - 4 \cdot 5 \cdot ( - 4) = 1 + 80 = 81\]

\[x_{1} = \frac{- 1 + 9}{10} = \frac{8}{10} = 0,8\]

\[x_{2} = \frac{- 1 - 9}{10} = - \frac{10}{10} = - 1\]

\[Ответ:x_{1} = 0,8;\ \ x_{2} = - 1.\]