6x^2-30x-84=0

解

6 x^{2} - 30 x - 84 = 0

x = 7, x = - 2

解答ステップ

6 x^{2} - 30 x - 84 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 30 ) \pm ( - 30 ) ^{2} - 4 \cdot 6 ( - 84 )}{2 \cdot 6}

(- 30)^{2} - 4 \cdot 6 (- 84) = 54

x_{1, 2} = \frac{- ( - 30 ) \pm 54}{2 \cdot 6}

解を分離する

x_{1} = \frac{- ( - 30 ) + 54}{2 \cdot 6}, x_{2} = \frac{- ( - 30 ) - 54}{2 \cdot 6}

x = \frac{- ( - 30 ) + 54}{2 \cdot 6} : 7

x = \frac{- ( - 30 ) - 54}{2 \cdot 6} : - 2

二次equationの解:

x = 7, x = - 2