x^2+5x-a=0

解答

x^{2} + 5 x - a = 0

x = \frac{- 5 + 25 + 4 a}{2}, x = \frac{- 5 - 25 + 4 a}{2}

求解步骤

x^{2} + 5 x - a = 0

使用求根公式求解

x_{1, 2} = \frac{- 5 \pm 5 ^{2} - 4 \cdot 1 \cdot ( - a )}{2 \cdot 1}

化简

5^{2} - 4 \cdot 1 \cdot (- a) : 25 + 4 a

x_{1, 2} = \frac{- 5 \pm 25 + 4 a}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- 5 + 25 + 4 a}{2 \cdot 1}, x_{2} = \frac{- 5 - 25 + 4 a}{2 \cdot 1}

x = \frac{- 5 + 25 + 4 a}{2 \cdot 1} : \frac{- 5 + 25 + 4 a}{2}

x = \frac{- 5 - 25 + 4 a}{2 \cdot 1} : \frac{- 5 - 25 + 4 a}{2}

二次方程组的解是:

x = \frac{- 5 + 25 + 4 a}{2}, x = \frac{- 5 - 25 + 4 a}{2}

- 4 x^{2} - 9 = 0

so l v e f or x, x^{2} - 6 x + 13 + y^{2} + 4 y = 0

so l v e f or x, x^{2} + (y - x \frac{2}{3})^{2} = 1

2 (\frac{x + 1}{3})^{2} = \frac{1}{2}

(\frac{43}{42.5}) n^{2} - n^{2} = 3