18x^2-72x-378=0

解

18 x^{2} - 72 x - 378 = 0

x = 7, x = - 3

解答ステップ

18 x^{2} - 72 x - 378 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 72 ) \pm ( - 72 ) ^{2} - 4 \cdot 18 ( - 378 )}{2 \cdot 18}

(- 72)^{2} - 4 \cdot 18 (- 378) = 180

x_{1, 2} = \frac{- ( - 72 ) \pm 180}{2 \cdot 18}

解を分離する

x_{1} = \frac{- ( - 72 ) + 180}{2 \cdot 18}, x_{2} = \frac{- ( - 72 ) - 180}{2 \cdot 18}

x = \frac{- ( - 72 ) + 180}{2 \cdot 18} : 7

x = \frac{- ( - 72 ) - 180}{2 \cdot 18} : - 3

二次equationの解:

x = 7, x = - 3