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受欢迎的代数 >

2x^2+2x-7=0

解答

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

解答

x = \frac{- 1 + 15}{2}, x = - \frac{1 + 15}{2}

+1

十进制

x = 1.43649 \dots, x = - 2.43649 \dots

求解步骤

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

使用求根公式求解

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

2^{2} - 4 \cdot 2 (- 7) = 215

x_{1, 2} = \frac{- 2 \pm 2 15}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- 2 + 2 15}{2 \cdot 2}, x_{2} = \frac{- 2 - 2 15}{2 \cdot 2}

x = \frac{- 2 + 2 15}{2 \cdot 2} : \frac{- 1 + 15}{2}

x = \frac{- 2 - 2 15}{2 \cdot 2} : - \frac{1 + 15}{2}

二次方程组的解是:

x = \frac{- 1 + 15}{2}, x = - \frac{1 + 15}{2}

作图

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