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受欢迎的代数 >

2/3 x=40-x^2

解答

\frac{2}{3} x = 40 - x^{2}

解答

x = - \frac{20}{3}, x = 6

+1

十进制

x = - 6.66666 \dots, x = 6

求解步骤

\frac{2}{3} x = 40 - x^{2}

在两边乘以

3

2 x = 120 - 3 x^{2}

交换两边

120 - 3 x^{2} = 2 x

将

2 x

para o lado esquerdo

120 - 3 x^{2} - 2 x = 0

改写成标准形式

a x^{2} + b x + c = 0

- 3 x^{2} - 2 x + 120 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 2 ) \pm ( - 2 ) ^{2} - 4 ( - 3 ) \cdot 120}{2 ( - 3 )}

(- 2)^{2} - 4 (- 3) \cdot 120 = 38

x_{1, 2} = \frac{- ( - 2 ) \pm 38}{2 ( - 3 )}

将解分隔开

x_{1} = \frac{- ( - 2 ) + 38}{2 ( - 3 )}, x_{2} = \frac{- ( - 2 ) - 38}{2 ( - 3 )}

x = \frac{- ( - 2 ) + 38}{2 ( - 3 )} : - \frac{20}{3}

x = \frac{- ( - 2 ) - 38}{2 ( - 3 )} : 6

二次方程组的解是:

x = - \frac{20}{3}, x = 6

作图

流行的例子

3 x^{2} - 10 x = 546

16 t^{2} - 80 t + 64 = 0

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3000 - 70 w = 100 w - w^{2}

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