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 >

31=(x+3)(x+6)

解答

31 = (x + 3) (x + 6)

解答

x = \frac{- 9 + 133}{2}, x = \frac{- 9 - 133}{2}

+1

十进制

x = 1.26628 \dots, x = - 10.26628 \dots

求解步骤

31 = (x + 3) (x + 6)

展开

(x + 3) (x + 6) : x^{2} + 9 x + 18

31 = x^{2} + 9 x + 18

交换两边

x^{2} + 9 x + 18 = 31

将

31

para o lado esquerdo

x^{2} + 9 x - 13 = 0

使用求根公式求解

x_{1, 2} = \frac{- 9 \pm 9 ^{2} - 4 \cdot 1 \cdot ( - 13 )}{2 \cdot 1}

9^{2} - 4 \cdot 1 \cdot (- 13) = 133

x_{1, 2} = \frac{- 9 \pm 133}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- 9 + 133}{2 \cdot 1}, x_{2} = \frac{- 9 - 133}{2 \cdot 1}

x = \frac{- 9 + 133}{2 \cdot 1} : \frac{- 9 + 133}{2}

x = \frac{- 9 - 133}{2 \cdot 1} : \frac{- 9 - 133}{2}

二次方程组的解是:

x = \frac{- 9 + 133}{2}, x = \frac{- 9 - 133}{2}

作图

流行的例子

completesquare-3x^2-12x-15

co m pl e t es q u a re - 3 x^{2} - 12 x - 15

x \cdot x - x = 6

0 = x - x^{2}

(x + 2) (x + 4) = 12

5*(x-5)^2-4x*(x+4)=13

5 \cdot (x - 5)^{2} - 4 x \cdot (x + 4) = 13