zs

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

受欢迎的代数 >

1x^2+7x+15=0

解答

1 x^{2} + 7 x + 15 = 0

解答

x = - \frac{7}{2} + i \frac{11}{2}, x = - \frac{7}{2} - i \frac{11}{2}

求解步骤

1 \cdot x^{2} + 7 x + 15 = 0

整理后得

x^{2} + 7 x + 15 = 0

使用求根公式求解

x_{1, 2} = \frac{- 7 \pm 7 ^{2} - 4 \cdot 1 \cdot 15}{2 \cdot 1}

化简

7^{2} - 4 \cdot 1 \cdot 15 : 11 i

x_{1, 2} = \frac{- 7 \pm 11 i}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- 7 + 11 i}{2 \cdot 1}, x_{2} = \frac{- 7 - 11 i}{2 \cdot 1}

x = \frac{- 7 + 11 i}{2 \cdot 1} : - \frac{7}{2} + i \frac{11}{2}

x = \frac{- 7 - 11 i}{2 \cdot 1} : - \frac{7}{2} - i \frac{11}{2}

二次方程组的解是:

x = - \frac{7}{2} + i \frac{11}{2}, x = - \frac{7}{2} - i \frac{11}{2}

作图

流行的例子

x^2+3x-24=3x+13x+1

x^{2} + 3 x - 24 = 3 x + 13 x + 1

x^{2} - 15 x - 4 = 0

12 x^{2} - 15 x + 4 = 0

(9+2x)(4+2x)=84

(9 + 2 x) (4 + 2 x) = 84

completesquare x^2+5x-4

co m pl e t es q u a re x^{2} + 5 x - 4