-x^2+78x+460=1581

解

- x^{2} + 78 x + 460 = 1581

x = 19, x = 59

解答ステップ

- x^{2} + 78 x + 460 = 1581

1581

を左側に移動します

- x^{2} + 78 x - 1121 = 0

解くとthe二次式

x_{1, 2} = \frac{- 78 \pm 7 8 ^{2} - 4 ( - 1 ) ( - 1121 )}{2 ( - 1 )}

7 8^{2} - 4 (- 1) (- 1121) = 40

x_{1, 2} = \frac{- 78 \pm 40}{2 ( - 1 )}

解を分離する

x_{1} = \frac{- 78 + 40}{2 ( - 1 )}, x_{2} = \frac{- 78 - 40}{2 ( - 1 )}

x = \frac{- 78 + 40}{2 ( - 1 )} : 19

x = \frac{- 78 - 40}{2 ( - 1 )} : 59

二次equationの解:

x = 19, x = 59