x^2-19x-120=0

解

x^{2} - 19 x - 120 = 0

x = 24, x = - 5

解答ステップ

x^{2} - 19 x - 120 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 19 ) \pm ( - 19 ) ^{2} - 4 \cdot 1 \cdot ( - 120 )}{2 \cdot 1}

(- 19)^{2} - 4 \cdot 1 \cdot (- 120) = 29

x_{1, 2} = \frac{- ( - 19 ) \pm 29}{2 \cdot 1}

解を分離する

x_{1} = \frac{- ( - 19 ) + 29}{2 \cdot 1}, x_{2} = \frac{- ( - 19 ) - 29}{2 \cdot 1}

x = \frac{- ( - 19 ) + 29}{2 \cdot 1} : 24

x = \frac{- ( - 19 ) - 29}{2 \cdot 1} : - 5

二次equationの解:

x = 24, x = - 5