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受欢迎的代数 >

2x^2-11x+21=0

解答

2 x^{2} - 11 x + 21 = 0

解答

x = \frac{11}{4} + i \frac{47}{4}, x = \frac{11}{4} - i \frac{47}{4}

求解步骤

2 x^{2} - 11 x + 21 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 11 ) \pm ( - 11 ) ^{2} - 4 \cdot 2 \cdot 21}{2 \cdot 2}

化简

(- 11)^{2} - 4 \cdot 2 \cdot 21 : 47 i

x_{1, 2} = \frac{- ( - 11 ) \pm 47 i}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- ( - 11 ) + 47 i}{2 \cdot 2}, x_{2} = \frac{- ( - 11 ) - 47 i}{2 \cdot 2}

x = \frac{- ( - 11 ) + 47 i}{2 \cdot 2} : \frac{11}{4} + i \frac{47}{4}

x = \frac{- ( - 11 ) - 47 i}{2 \cdot 2} : \frac{11}{4} - i \frac{47}{4}

二次方程组的解是:

x = \frac{11}{4} + i \frac{47}{4}, x = \frac{11}{4} - i \frac{47}{4}

作图

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