5x^2-20x-300=0

解

5 x^{2} - 20 x - 300 = 0

x = 10, x = - 6

解答ステップ

5 x^{2} - 20 x - 300 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 20 ) \pm ( - 20 ) ^{2} - 4 \cdot 5 ( - 300 )}{2 \cdot 5}

(- 20)^{2} - 4 \cdot 5 (- 300) = 80

x_{1, 2} = \frac{- ( - 20 ) \pm 80}{2 \cdot 5}

解を分離する

x_{1} = \frac{- ( - 20 ) + 80}{2 \cdot 5}, x_{2} = \frac{- ( - 20 ) - 80}{2 \cdot 5}

x = \frac{- ( - 20 ) + 80}{2 \cdot 5} : 10

x = \frac{- ( - 20 ) - 80}{2 \cdot 5} : - 6

二次equationの解:

x = 10, x = - 6