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受欢迎的代数 >

(x+5)(x-2)=60

解答

(x + 5) (x - 2) = 60

解答

x = 7, x = - 10

求解步骤

(x + 5) (x - 2) = 60

展开

(x + 5) (x - 2) : x^{2} + 3 x - 10

x^{2} + 3 x - 10 = 60

将

60

para o lado esquerdo

x^{2} + 3 x - 70 = 0

使用求根公式求解

x_{1, 2} = \frac{- 3 \pm 3 ^{2} - 4 \cdot 1 \cdot ( - 70 )}{2 \cdot 1}

3^{2} - 4 \cdot 1 \cdot (- 70) = 17

x_{1, 2} = \frac{- 3 \pm 17}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- 3 + 17}{2 \cdot 1}, x_{2} = \frac{- 3 - 17}{2 \cdot 1}

x = \frac{- 3 + 17}{2 \cdot 1} : 7

x = \frac{- 3 - 17}{2 \cdot 1} : - 10

二次方程组的解是:

x = 7, x = - 10

作图

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