t^2+8t+15=0

解

t^{2} + 8 t + 15 = 0

t = - 3, t = - 5

解答ステップ

t^{2} + 8 t + 15 = 0

解くとthe二次式

t_{1, 2} = \frac{- 8 \pm 8 ^{2} - 4 \cdot 1 \cdot 15}{2 \cdot 1}

8^{2} - 4 \cdot 1 \cdot 15 = 2

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

解を分離する

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

t = \frac{- 8 + 2}{2 \cdot 1} : - 3

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

二次equationの解:

t = - 3, t = - 5