u^2-10u+21=0

解

u^{2} - 10 u + 21 = 0

u = 7, u = 3

解答ステップ

u^{2} - 10 u + 21 = 0

解くとthe二次式

u_{1, 2} = \frac{- ( - 10 ) \pm ( - 10 ) ^{2} - 4 \cdot 1 \cdot 21}{2 \cdot 1}

(- 10)^{2} - 4 \cdot 1 \cdot 21 = 4

u_{1, 2} = \frac{- ( - 10 ) \pm 4}{2 \cdot 1}

解を分離する

u_{1} = \frac{- ( - 10 ) + 4}{2 \cdot 1}, u_{2} = \frac{- ( - 10 ) - 4}{2 \cdot 1}

u = \frac{- ( - 10 ) + 4}{2 \cdot 1} : 7

u = \frac{- ( - 10 ) - 4}{2 \cdot 1} : 3

二次equationの解:

u = 7, u = 3