x^2-5x-1=0

解答

x^{2} - 5 x - 1 = 0

x = \frac{5 + 29}{2}, x = \frac{5 - 29}{2}

十进制

x = 5.19258 \dots, x = - 0.19258 \dots

求解步骤

x^{2} - 5 x - 1 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 5 ) \pm ( - 5 ) ^{2} - 4 \cdot 1 \cdot ( - 1 )}{2 \cdot 1}

(- 5)^{2} - 4 \cdot 1 \cdot (- 1) = 29

x_{1, 2} = \frac{- ( - 5 ) \pm 29}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- ( - 5 ) + 29}{2 \cdot 1}, x_{2} = \frac{- ( - 5 ) - 29}{2 \cdot 1}

x = \frac{- ( - 5 ) + 29}{2 \cdot 1} : \frac{5 + 29}{2}

x = \frac{- ( - 5 ) - 29}{2 \cdot 1} : \frac{5 - 29}{2}

二次方程组的解是:

x = \frac{5 + 29}{2}, x = \frac{5 - 29}{2}

s im pl i f y \frac{3}{5} m^{2} - 2 mn + \frac{1}{10} m^{2} - \frac{1}{3} mn + 2 mn - 2 m^{2}

s im pl i f y 3 (1 1^{\frac{1}{4}}) + 9 (1 1^{\frac{1}{4}})

s im pl i f y 3 (2)

\frac{7 x - 1}{3} \geq \frac{x + 2}{4}

s im pl i f y 0.8 1^{- 1 \cdot 2} + \frac{1}{1 - 0.81}