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=7

解答

2 x^{2} + 5 x = 7

解答

x = 1, x = - \frac{7}{2}

+1

十进制

x = 1, x = - 3.5

求解步骤

2 x^{2} + 5 x = 7

将

7

para o lado esquerdo

2 x^{2} + 5 x - 7 = 0

使用求根公式求解

x_{1, 2} = \frac{- 5 \pm 5 ^{2} - 4 \cdot 2 ( - 7 )}{2 \cdot 2}

5^{2} - 4 \cdot 2 (- 7) = 9

x_{1, 2} = \frac{- 5 \pm 9}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- 5 + 9}{2 \cdot 2}, x_{2} = \frac{- 5 - 9}{2 \cdot 2}

x = \frac{- 5 + 9}{2 \cdot 2} : 1

x = \frac{- 5 - 9}{2 \cdot 2} : - \frac{7}{2}

二次方程组的解是:

x = 1, x = - \frac{7}{2}

作图

流行的例子

x^{2} + 0.7 = 2.4 x

- 4 x^{2} + 9 = 0

completesquare x^2-7x

co m pl e t es q u a re x^{2} - 7 x

2 x^{2} - 6 x + 12 = 0

completesquare x^2-2x+2

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