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受欢迎的代数 >

2r^2-8r=-64

解答

2 r^{2} - 8 r = - 64

解答

r = 2 + 27 i, r = 2 - 27 i

求解步骤

2 r^{2} - 8 r = - 64

将

64

para o lado esquerdo

2 r^{2} - 8 r + 64 = 0

使用求根公式求解

r_{1, 2} = \frac{- ( - 8 ) \pm ( - 8 ) ^{2} - 4 \cdot 2 \cdot 64}{2 \cdot 2}

化简

(- 8)^{2} - 4 \cdot 2 \cdot 64 : 87 i

r_{1, 2} = \frac{- ( - 8 ) \pm 8 7 i}{2 \cdot 2}

将解分隔开

r_{1} = \frac{- ( - 8 ) + 8 7 i}{2 \cdot 2}, r_{2} = \frac{- ( - 8 ) - 8 7 i}{2 \cdot 2}

r = \frac{- ( - 8 ) + 8 7 i}{2 \cdot 2} : 2 + 27 i

r = \frac{- ( - 8 ) - 8 7 i}{2 \cdot 2} : 2 - 27 i

二次方程组的解是:

r = 2 + 27 i, r = 2 - 27 i

作图

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