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受欢迎的代数 >

7x^2-7x-1=0

解答

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

解答

x = \frac{7 + 77}{14}, x = \frac{7 - 77}{14}

+1

十进制

x = 1.12678 \dots, x = - 0.12678 \dots

求解步骤

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

使用求根公式求解

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

(- 7)^{2} - 4 \cdot 7 (- 1) = 77

x_{1, 2} = \frac{- ( - 7 ) \pm 77}{2 \cdot 7}

将解分隔开

x_{1} = \frac{- ( - 7 ) + 77}{2 \cdot 7}, x_{2} = \frac{- ( - 7 ) - 77}{2 \cdot 7}

x = \frac{- ( - 7 ) + 77}{2 \cdot 7} : \frac{7 + 77}{14}

x = \frac{- ( - 7 ) - 77}{2 \cdot 7} : \frac{7 - 77}{14}

二次方程组的解是:

x = \frac{7 + 77}{14}, x = \frac{7 - 77}{14}

作图

流行的例子

4 x - 3 > 3 x + 5

5 + x = \frac{7 x}{4} + \frac{1}{2}

化简 (40-20(10))/(10^2)+1/2

s im pl i f y \frac{40 - 20 ( 10 )}{1 0 ^{2}} + \frac{1}{2}

12531r^2-4445060.66r+160070813=0

12531 r^{2} - 4445060.66 r + 160070813 = 0

化简 (-2)/(-2)

s im pl i f y \frac{- 2}{- 2}