2x^2-10x+9=0

解答

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

x = \frac{5 + 7}{2}, x = \frac{5 - 7}{2}

十进制

x = 3.82287 \dots, x = 1.17712 \dots

求解步骤

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

使用求根公式求解

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

(- 10)^{2} - 4 \cdot 2 \cdot 9 = 27

x_{1, 2} = \frac{- ( - 10 ) \pm 2 7}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- ( - 10 ) + 2 7}{2 \cdot 2}, x_{2} = \frac{- ( - 10 ) - 2 7}{2 \cdot 2}

x = \frac{- ( - 10 ) + 2 7}{2 \cdot 2} : \frac{5 + 7}{2}

x = \frac{- ( - 10 ) - 2 7}{2 \cdot 2} : \frac{5 - 7}{2}

二次方程组的解是:

x = \frac{5 + 7}{2}, x = \frac{5 - 7}{2}

1.04 x^{2} + 0.102 x - 0.935 = 0

(k - 2) x^{2} - (2 k - 1) x + k - 1 = 0

x^{2} - 2 x - 28 = - 6 x + 4 - 6 x + 4

2 x (x - 14) + 11 (3 + x) = - 22 x + 27 + x^{2}

so l v e f or t, y = v t + \frac{1}{2} g t^{2}