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受欢迎的代数 >

x^2-14x-40=0

解答

x^{2} - 14 x - 40 = 0

解答

x = 7 + 89, x = 7 - 89

+1

十进制

x = 16.43398 \dots, x = - 2.43398 \dots

求解步骤

x^{2} - 14 x - 40 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 14 ) \pm ( - 14 ) ^{2} - 4 \cdot 1 \cdot ( - 40 )}{2 \cdot 1}

(- 14)^{2} - 4 \cdot 1 \cdot (- 40) = 289

x_{1, 2} = \frac{- ( - 14 ) \pm 2 89}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- ( - 14 ) + 2 89}{2 \cdot 1}, x_{2} = \frac{- ( - 14 ) - 2 89}{2 \cdot 1}

x = \frac{- ( - 14 ) + 2 89}{2 \cdot 1} : 7 + 89

x = \frac{- ( - 14 ) - 2 89}{2 \cdot 1} : 7 - 89

二次方程组的解是:

x = 7 + 89, x = 7 - 89

作图

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