-5x^2+10x+15=0

解

- 5 x^{2} + 10 x + 15 = 0

x = - 1, x = 3

解答ステップ

- 5 x^{2} + 10 x + 15 = 0

解くとthe二次式

x_{1, 2} = \frac{- 10 \pm 1 0 ^{2} - 4 ( - 5 ) \cdot 15}{2 ( - 5 )}

1 0^{2} - 4 (- 5) \cdot 15 = 20

x_{1, 2} = \frac{- 10 \pm 20}{2 ( - 5 )}

解を分離する

x_{1} = \frac{- 10 + 20}{2 ( - 5 )}, x_{2} = \frac{- 10 - 20}{2 ( - 5 )}

x = \frac{- 10 + 20}{2 ( - 5 )} : - 1

x = \frac{- 10 - 20}{2 ( - 5 )} : 3

二次equationの解:

x = - 1, x = 3