d^2+7d+10=0

解

d^{2} + 7 d + 10 = 0

d = - 2, d = - 5

解答ステップ

d^{2} + 7 d + 10 = 0

解くとthe二次式

d_{1, 2} = \frac{- 7 \pm 7 ^{2} - 4 \cdot 1 \cdot 10}{2 \cdot 1}

7^{2} - 4 \cdot 1 \cdot 10 = 3

d_{1, 2} = \frac{- 7 \pm 3}{2 \cdot 1}

解を分離する

d_{1} = \frac{- 7 + 3}{2 \cdot 1}, d_{2} = \frac{- 7 - 3}{2 \cdot 1}

d = \frac{- 7 + 3}{2 \cdot 1} : - 2

d = \frac{- 7 - 3}{2 \cdot 1} : - 5

二次equationの解:

d = - 2, d = - 5