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受欢迎的代数 >

-x(x+7)=(x-2)(x+2)

解答

- x (x + 7) = (x - 2) (x + 2)

解答

x = - 4, x = \frac{1}{2}

+1

十进制

x = - 4, x = 0.5

求解步骤

- x (x + 7) = (x - 2) (x + 2)

展开

- x (x + 7) : - x^{2} - 7 x

展开

(x - 2) (x + 2) : x^{2} - 4

- x^{2} - 7 x = x^{2} - 4

将

4

para o lado esquerdo

- x^{2} - 7 x + 4 = x^{2}

将

x^{2}

para o lado esquerdo

- 2 x^{2} - 7 x + 4 = 0

使用求根公式求解

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

(- 7)^{2} - 4 (- 2) \cdot 4 = 9

x_{1, 2} = \frac{- ( - 7 ) \pm 9}{2 ( - 2 )}

将解分隔开

x_{1} = \frac{- ( - 7 ) + 9}{2 ( - 2 )}, x_{2} = \frac{- ( - 7 ) - 9}{2 ( - 2 )}

x = \frac{- ( - 7 ) + 9}{2 ( - 2 )} : - 4

x = \frac{- ( - 7 ) - 9}{2 ( - 2 )} : \frac{1}{2}

二次方程组的解是:

x = - 4, x = \frac{1}{2}

作图

流行的例子

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