r^2-5r-6=0

解

r^{2} - 5 r - 6 = 0

r = 6, r = - 1

解答ステップ

r^{2} - 5 r - 6 = 0

解くとthe二次式

r_{1, 2} = \frac{- ( - 5 ) \pm ( - 5 ) ^{2} - 4 \cdot 1 \cdot ( - 6 )}{2 \cdot 1}

(- 5)^{2} - 4 \cdot 1 \cdot (- 6) = 7

r_{1, 2} = \frac{- ( - 5 ) \pm 7}{2 \cdot 1}

解を分離する

r_{1} = \frac{- ( - 5 ) + 7}{2 \cdot 1}, r_{2} = \frac{- ( - 5 ) - 7}{2 \cdot 1}

r = \frac{- ( - 5 ) + 7}{2 \cdot 1} : 6

r = \frac{- ( - 5 ) - 7}{2 \cdot 1} : - 1

二次equationの解:

r = 6, r = - 1