-7x^2+2x-1=0

解答

- 7 x^{2} + 2 x - 1 = 0

x = \frac{1}{7} - i \frac{6}{7}, x = \frac{1}{7} + i \frac{6}{7}

求解步骤

- 7 x^{2} + 2 x - 1 = 0

使用求根公式求解

x_{1, 2} = \frac{- 2 \pm 2 ^{2} - 4 ( - 7 ) ( - 1 )}{2 ( - 7 )}

化简

2^{2} - 4 (- 7) (- 1) : 26 i

x_{1, 2} = \frac{- 2 \pm 2 6 i}{2 ( - 7 )}

将解分隔开

x_{1} = \frac{- 2 + 2 6 i}{2 ( - 7 )}, x_{2} = \frac{- 2 - 2 6 i}{2 ( - 7 )}

x = \frac{- 2 + 2 6 i}{2 ( - 7 )} : \frac{1}{7} - i \frac{6}{7}

x = \frac{- 2 - 2 6 i}{2 ( - 7 )} : \frac{1}{7} + i \frac{6}{7}

二次方程组的解是:

x = \frac{1}{7} - i \frac{6}{7}, x = \frac{1}{7} + i \frac{6}{7}

x^{2} = 47

- 3.35179 \cdot \frac{t ^{2}}{2} + 4.1 t = 0

4 x - 1 \leq 5 x \leq 3 (x + 2)

(x + 9) (x - 3) = (x + 1)^{2}

s im pl i f y (- \frac{27}{125})^{\frac{- 2}{3}}