1-0.4x+0.04x^2=0

解

1 - 0.4 x + 0.04 x^{2} = 0

x = 5

解答ステップ

1 - 0.4 x + 0.04 x^{2} = 0

以下で両辺を乗じる:

100

100 - 40 x + 4 x^{2} = 0

標準的な形式で書く

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

4 x^{2} - 40 x + 100 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 40 ) \pm ( - 40 ) ^{2} - 4 \cdot 4 \cdot 100}{2 \cdot 4}

(- 40)^{2} - 4 \cdot 4 \cdot 100 = 0

x_{1, 2} = \frac{- ( - 40 ) \pm 0}{2 \cdot 4}

x = \frac{- ( - 40 )}{2 \cdot 4}

\frac{- ( - 40 )}{2 \cdot 4} = 5

x = 5

二次equationの解:

x = 5