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受欢迎的代数 >

2x^2-7x=1

解答

2 x^{2} - 7 x = 1

解答

x = \frac{7 + 57}{4}, x = \frac{7 - 57}{4}

+1

十进制

x = 3.63745 \dots, x = - 0.13745 \dots

求解步骤

2 x^{2} - 7 x = 1

将

1

para o lado esquerdo

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

使用求根公式求解

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

(- 7)^{2} - 4 \cdot 2 (- 1) = 57

x_{1, 2} = \frac{- ( - 7 ) \pm 57}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- ( - 7 ) + 57}{2 \cdot 2}, x_{2} = \frac{- ( - 7 ) - 57}{2 \cdot 2}

x = \frac{- ( - 7 ) + 57}{2 \cdot 2} : \frac{7 + 57}{4}

x = \frac{- ( - 7 ) - 57}{2 \cdot 2} : \frac{7 - 57}{4}

二次方程组的解是:

x = \frac{7 + 57}{4}, x = \frac{7 - 57}{4}

作图

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