solvefor x,x^2+8x+11=0

解

x, x^{2} + 8 x + 11 = 0

x = - 4 + 5, x = - 4 - 5

十進法表記

x = - 1.76393 \dots, x = - 6.23606 \dots

解答ステップ

x^{2} + 8 x + 11 = 0

解くとthe二次式

x_{1, 2} = \frac{- 8 \pm 8 ^{2} - 4 \cdot 1 \cdot 11}{2 \cdot 1}

8^{2} - 4 \cdot 1 \cdot 11 = 25

x_{1, 2} = \frac{- 8 \pm 2 5}{2 \cdot 1}

解を分離する

x_{1} = \frac{- 8 + 2 5}{2 \cdot 1}, x_{2} = \frac{- 8 - 2 5}{2 \cdot 1}

x = \frac{- 8 + 2 5}{2 \cdot 1} : - 4 + 5

x = \frac{- 8 - 2 5}{2 \cdot 1} : - 4 - 5

二次equationの解:

x = - 4 + 5, x = - 4 - 5