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 >

2x^2+5x-8= 5/2 x+20

解答

2 x^{2} + 5 x - 8 = \frac{5}{2} x + 20

解答

x = \frac{- 5 + 921}{8}, x = \frac{- 5 - 921}{8}

+1

十进制

x = 3.16849 \dots, x = - 4.41849 \dots

求解步骤

2 x^{2} + 5 x - 8 = \frac{5}{2} x + 20

在两边乘以

2

4 x^{2} + 10 x - 16 = 5 x + 40

将

40

para o lado esquerdo

4 x^{2} + 10 x - 56 = 5 x

将

5 x

para o lado esquerdo

4 x^{2} + 5 x - 56 = 0

使用求根公式求解

x_{1, 2} = \frac{- 5 \pm 5 ^{2} - 4 \cdot 4 ( - 56 )}{2 \cdot 4}

5^{2} - 4 \cdot 4 (- 56) = 921

x_{1, 2} = \frac{- 5 \pm 921}{2 \cdot 4}

将解分隔开

x_{1} = \frac{- 5 + 921}{2 \cdot 4}, x_{2} = \frac{- 5 - 921}{2 \cdot 4}

x = \frac{- 5 + 921}{2 \cdot 4} : \frac{- 5 + 921}{8}

x = \frac{- 5 - 921}{2 \cdot 4} : \frac{- 5 - 921}{8}

二次方程组的解是:

x = \frac{- 5 + 921}{8}, x = \frac{- 5 - 921}{8}

作图

流行的例子

x^{2} - 28 x + 16 = 0

9x^{(2)}-6x-11=0

9 x^{(2)} - 6 x - 11 = 0

5 x^{2} + 32 x + 27 = 0

x^2+4000x-12000000=0

x^{2} + 4000 x - 12000000 = 0

11 x^{2} - 3 = 0