3x^2+36x+81=0

解

3 x^{2} + 36 x + 81 = 0

x = - 3, x = - 9

解答ステップ

3 x^{2} + 36 x + 81 = 0

解くとthe二次式

x_{1, 2} = \frac{- 36 \pm 3 6 ^{2} - 4 \cdot 3 \cdot 81}{2 \cdot 3}

3 6^{2} - 4 \cdot 3 \cdot 81 = 18

x_{1, 2} = \frac{- 36 \pm 18}{2 \cdot 3}

解を分離する

x_{1} = \frac{- 36 + 18}{2 \cdot 3}, x_{2} = \frac{- 36 - 18}{2 \cdot 3}

x = \frac{- 36 + 18}{2 \cdot 3} : - 3

x = \frac{- 36 - 18}{2 \cdot 3} : - 9

二次equationの解:

x = - 3, x = - 9