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受欢迎的代数 >

x^2+10x+31=15x+21

解答

x^{2} + 10 x + 31 = 15 x + 21

解答

x = \frac{5}{2} + i \frac{15}{2}, x = \frac{5}{2} - i \frac{15}{2}

求解步骤

x^{2} + 10 x + 31 = 15 x + 21

将

21

para o lado esquerdo

x^{2} + 10 x + 10 = 15 x

将

15 x

para o lado esquerdo

x^{2} - 5 x + 10 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 5 ) \pm ( - 5 ) ^{2} - 4 \cdot 1 \cdot 10}{2 \cdot 1}

化简

(- 5)^{2} - 4 \cdot 1 \cdot 10 : 15 i

x_{1, 2} = \frac{- ( - 5 ) \pm 15 i}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- ( - 5 ) + 15 i}{2 \cdot 1}, x_{2} = \frac{- ( - 5 ) - 15 i}{2 \cdot 1}

x = \frac{- ( - 5 ) + 15 i}{2 \cdot 1} : \frac{5}{2} + i \frac{15}{2}

x = \frac{- ( - 5 ) - 15 i}{2 \cdot 1} : \frac{5}{2} - i \frac{15}{2}

二次方程组的解是:

x = \frac{5}{2} + i \frac{15}{2}, x = \frac{5}{2} - i \frac{15}{2}

作图

流行的例子

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