-x^2+3x+40=0

解

- x^{2} + 3 x + 40 = 0

x = - 5, x = 8

解答ステップ

- x^{2} + 3 x + 40 = 0

解くとthe二次式

x_{1, 2} = \frac{- 3 \pm 3 ^{2} - 4 ( - 1 ) \cdot 40}{2 ( - 1 )}

3^{2} - 4 (- 1) \cdot 40 = 13

x_{1, 2} = \frac{- 3 \pm 13}{2 ( - 1 )}

解を分離する

x_{1} = \frac{- 3 + 13}{2 ( - 1 )}, x_{2} = \frac{- 3 - 13}{2 ( - 1 )}

x = \frac{- 3 + 13}{2 ( - 1 )} : - 5

x = \frac{- 3 - 13}{2 ( - 1 )} : 8

二次equationの解:

x = - 5, x = 8