ja

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

人気のある代数 >

7x^2-4x-8=0

解

7 x^{2} - 4 x - 8 = 0

解

x = \frac{2 ( 1 + 15 )}{7}, x = \frac{2 ( 1 - 15 )}{7}

+1

十進法表記

x = 1.39228 \dots, x = - 0.82085 \dots

解答ステップ

7 x^{2} - 4 x - 8 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 4 ) \pm ( - 4 ) ^{2} - 4 \cdot 7 ( - 8 )}{2 \cdot 7}

(- 4)^{2} - 4 \cdot 7 (- 8) = 415

x_{1, 2} = \frac{- ( - 4 ) \pm 4 15}{2 \cdot 7}

解を分離する

x_{1} = \frac{- ( - 4 ) + 4 15}{2 \cdot 7}, x_{2} = \frac{- ( - 4 ) - 4 15}{2 \cdot 7}

x = \frac{- ( - 4 ) + 4 15}{2 \cdot 7} : \frac{2 ( 1 + 15 )}{7}

x = \frac{- ( - 4 ) - 4 15}{2 \cdot 7} : \frac{2 ( 1 - 15 )}{7}

二次equationの解:

x = \frac{2 ( 1 + 15 )}{7}, x = \frac{2 ( 1 - 15 )}{7}

グラフ

人気の例

x^{2} + 8.5 x + 18 = 0

(2 x - 3)^{2} - 1 = 0

x^{2} - 16 x + 145 = 0

x^{2} - 3 x + \frac{9}{4} = 6

1 2^{2} + 8^{2} = c^{2}