2x^2+18x+40=0

解

2 x^{2} + 18 x + 40 = 0

x = - 4, x = - 5

解答ステップ

2 x^{2} + 18 x + 40 = 0

解くとthe二次式

x_{1, 2} = \frac{- 18 \pm 1 8 ^{2} - 4 \cdot 2 \cdot 40}{2 \cdot 2}

1 8^{2} - 4 \cdot 2 \cdot 40 = 2

x_{1, 2} = \frac{- 18 \pm 2}{2 \cdot 2}

解を分離する

x_{1} = \frac{- 18 + 2}{2 \cdot 2}, x_{2} = \frac{- 18 - 2}{2 \cdot 2}

x = \frac{- 18 + 2}{2 \cdot 2} : - 4

x = \frac{- 18 - 2}{2 \cdot 2} : - 5

二次equationの解:

x = - 4, x = - 5