p^2-3p-18=0

解

p^{2} - 3 p - 18 = 0

p = 6, p = - 3

解答ステップ

p^{2} - 3 p - 18 = 0

解くとthe二次式

p_{1, 2} = \frac{- ( - 3 ) \pm ( - 3 ) ^{2} - 4 \cdot 1 \cdot ( - 18 )}{2 \cdot 1}

(- 3)^{2} - 4 \cdot 1 \cdot (- 18) = 9

p_{1, 2} = \frac{- ( - 3 ) \pm 9}{2 \cdot 1}

解を分離する

p_{1} = \frac{- ( - 3 ) + 9}{2 \cdot 1}, p_{2} = \frac{- ( - 3 ) - 9}{2 \cdot 1}

p = \frac{- ( - 3 ) + 9}{2 \cdot 1} : 6

p = \frac{- ( - 3 ) - 9}{2 \cdot 1} : - 3

二次equationの解:

p = 6, p = - 3