12x^2-280x+1200=0

解

12 x^{2} - 280 x + 1200 = 0

x = \frac{5 ( 7 + 13 )}{3}, x = \frac{5 ( 7 - 13 )}{3}

十進法表記

x = 17.67591 \dots, x = 5.65741 \dots

解答ステップ

12 x^{2} - 280 x + 1200 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 280 ) \pm ( - 280 ) ^{2} - 4 \cdot 12 \cdot 1200}{2 \cdot 12}

(- 280)^{2} - 4 \cdot 12 \cdot 1200 = 4013

x_{1, 2} = \frac{- ( - 280 ) \pm 40 13}{2 \cdot 12}

解を分離する

x_{1} = \frac{- ( - 280 ) + 40 13}{2 \cdot 12}, x_{2} = \frac{- ( - 280 ) - 40 13}{2 \cdot 12}

x = \frac{- ( - 280 ) + 40 13}{2 \cdot 12} : \frac{5 ( 7 + 13 )}{3}

x = \frac{- ( - 280 ) - 40 13}{2 \cdot 12} : \frac{5 ( 7 - 13 )}{3}

二次equationの解:

x = \frac{5 ( 7 + 13 )}{3}, x = \frac{5 ( 7 - 13 )}{3}