(-a)^2-4(1)(-2a)=0

解

(- a)^{2} - 4 (1) (- 2 a) = 0

a = 0, a = - 8

解答ステップ

(- a)^{2} - 4 (1) (- 2 a) = 0

拡張

(- a)^{2} - 4 (1) (- 2 a) : a^{2} + 8 a

a^{2} + 8 a = 0

解くとthe二次式

a_{1, 2} = \frac{- 8 \pm 8 ^{2} - 4 \cdot 1 \cdot 0}{2 \cdot 1}

8^{2} - 4 \cdot 1 \cdot 0 = 8

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

解を分離する

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

a = \frac{- 8 + 8}{2 \cdot 1} : 0

a = \frac{- 8 - 8}{2 \cdot 1} : - 8

二次equationの解:

a = 0, a = - 8