4x^2-16x-20=0

解

4 x^{2} - 16 x - 20 = 0

x = 5, x = - 1

解答ステップ

4 x^{2} - 16 x - 20 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 16 ) \pm ( - 16 ) ^{2} - 4 \cdot 4 ( - 20 )}{2 \cdot 4}

(- 16)^{2} - 4 \cdot 4 (- 20) = 24

x_{1, 2} = \frac{- ( - 16 ) \pm 24}{2 \cdot 4}

解を分離する

x_{1} = \frac{- ( - 16 ) + 24}{2 \cdot 4}, x_{2} = \frac{- ( - 16 ) - 24}{2 \cdot 4}

x = \frac{- ( - 16 ) + 24}{2 \cdot 4} : 5

x = \frac{- ( - 16 ) - 24}{2 \cdot 4} : - 1

二次equationの解:

x = 5, x = - 1