t^2+9t+20=0

解

t^{2} + 9 t + 20 = 0

t = - 4, t = - 5

解答ステップ

t^{2} + 9 t + 20 = 0

解くとthe二次式

t_{1, 2} = \frac{- 9 \pm 9 ^{2} - 4 \cdot 1 \cdot 20}{2 \cdot 1}

9^{2} - 4 \cdot 1 \cdot 20 = 1

t_{1, 2} = \frac{- 9 \pm 1}{2 \cdot 1}

解を分離する

t_{1} = \frac{- 9 + 1}{2 \cdot 1}, t_{2} = \frac{- 9 - 1}{2 \cdot 1}

t = \frac{- 9 + 1}{2 \cdot 1} : - 4

t = \frac{- 9 - 1}{2 \cdot 1} : - 5

二次equationの解:

t = - 4, t = - 5