3u^2+15u=0

解

3 u^{2} + 15 u = 0

u = 0, u = - 5

解答ステップ

3 u^{2} + 15 u = 0

解くとthe二次式

u_{1, 2} = \frac{- 15 \pm 1 5 ^{2} - 4 \cdot 3 \cdot 0}{2 \cdot 3}

1 5^{2} - 4 \cdot 3 \cdot 0 = 15

u_{1, 2} = \frac{- 15 \pm 15}{2 \cdot 3}

解を分離する

u_{1} = \frac{- 15 + 15}{2 \cdot 3}, u_{2} = \frac{- 15 - 15}{2 \cdot 3}

u = \frac{- 15 + 15}{2 \cdot 3} : 0

u = \frac{- 15 - 15}{2 \cdot 3} : - 5

二次equationの解:

u = 0, u = - 5