r^2-10r+9=0

解

r^{2} - 10 r + 9 = 0

r = 9, r = 1

解答ステップ

r^{2} - 10 r + 9 = 0

解くとthe二次式

r_{1, 2} = \frac{- ( - 10 ) \pm ( - 10 ) ^{2} - 4 \cdot 1 \cdot 9}{2 \cdot 1}

(- 10)^{2} - 4 \cdot 1 \cdot 9 = 8

r_{1, 2} = \frac{- ( - 10 ) \pm 8}{2 \cdot 1}

解を分離する

r_{1} = \frac{- ( - 10 ) + 8}{2 \cdot 1}, r_{2} = \frac{- ( - 10 ) - 8}{2 \cdot 1}

r = \frac{- ( - 10 ) + 8}{2 \cdot 1} : 9

r = \frac{- ( - 10 ) - 8}{2 \cdot 1} : 1

二次equationの解:

r = 9, r = 1