solvefor x,21.8x^2-202x-60=0

解答

x, 21.8 x^{2} - 202 x - 60 = 0

x = \frac{5 ( 101 + 11509 )}{109}, x = \frac{5 ( 101 - 11509 )}{109}

十进制

x = 9.55412 \dots, x = - 0.28807 \dots

求解步骤

21.8 x^{2} - 202 x - 60 = 0

在两边乘以

10

218 x^{2} - 2020 x - 600 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 2020 ) \pm ( - 2020 ) ^{2} - 4 \cdot 218 ( - 600 )}{2 \cdot 218}

(- 2020)^{2} - 4 \cdot 218 (- 600) = 2011509

x_{1, 2} = \frac{- ( - 2020 ) \pm 20 11509}{2 \cdot 218}

将解分隔开

x_{1} = \frac{- ( - 2020 ) + 20 11509}{2 \cdot 218}, x_{2} = \frac{- ( - 2020 ) - 20 11509}{2 \cdot 218}

x = \frac{- ( - 2020 ) + 20 11509}{2 \cdot 218} : \frac{5 ( 101 + 11509 )}{109}

x = \frac{- ( - 2020 ) - 20 11509}{2 \cdot 218} : \frac{5 ( 101 - 11509 )}{109}

二次方程组的解是:

x = \frac{5 ( 101 + 11509 )}{109}, x = \frac{5 ( 101 - 11509 )}{109}

so l v e f or x, 4 x^{2} + 8 y^{2} - 4 z^{2} = 0

so l v e f or x, x^{2} + K x + 9 = 0

so l v e f or x, 9 x^{2} - 4 y^{2} - z^{2} + 16 y - 17 = 0

x^{2} - 4 x - 26 = - 2

400 = n (\frac{2 ( - 5 ) + 4 ( n - 1 )}{2})