y^2-13y-30=0

解

y^{2} - 13 y - 30 = 0

y = 15, y = - 2

解答ステップ

y^{2} - 13 y - 30 = 0

解くとthe二次式

y_{1, 2} = \frac{- ( - 13 ) \pm ( - 13 ) ^{2} - 4 \cdot 1 \cdot ( - 30 )}{2 \cdot 1}

(- 13)^{2} - 4 \cdot 1 \cdot (- 30) = 17

y_{1, 2} = \frac{- ( - 13 ) \pm 17}{2 \cdot 1}

解を分離する

y_{1} = \frac{- ( - 13 ) + 17}{2 \cdot 1}, y_{2} = \frac{- ( - 13 ) - 17}{2 \cdot 1}

y = \frac{- ( - 13 ) + 17}{2 \cdot 1} : 15

y = \frac{- ( - 13 ) - 17}{2 \cdot 1} : - 2

二次equationの解:

y = 15, y = - 2