quadraticformula 2x^2-3x-5=0

解

2 x^{2} - 3 x - 5 = 0

x = \frac{5}{2}, x = - 1

十進法表記

x = 2.5, x = - 1

解答ステップ

2 x^{2} - 3 x - 5 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 3 ) \pm ( - 3 ) ^{2} - 4 \cdot 2 ( - 5 )}{2 \cdot 2}

(- 3)^{2} - 4 \cdot 2 (- 5) = 7

x_{1, 2} = \frac{- ( - 3 ) \pm 7}{2 \cdot 2}

解を分離する

x_{1} = \frac{- ( - 3 ) + 7}{2 \cdot 2}, x_{2} = \frac{- ( - 3 ) - 7}{2 \cdot 2}

x = \frac{- ( - 3 ) + 7}{2 \cdot 2} : \frac{5}{2}

x = \frac{- ( - 3 ) - 7}{2 \cdot 2} : - 1

二次equationの解:

x = \frac{5}{2}, x = - 1