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 >

-x^2-7x=-18

解答

- x^{2} - 7 x = - 18

解答

x = - 9, x = 2

求解步骤

- x^{2} - 7 x = - 18

将

18

para o lado esquerdo

- x^{2} - 7 x + 18 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 7 ) \pm ( - 7 ) ^{2} - 4 ( - 1 ) \cdot 18}{2 ( - 1 )}

(- 7)^{2} - 4 (- 1) \cdot 18 = 11

x_{1, 2} = \frac{- ( - 7 ) \pm 11}{2 ( - 1 )}

将解分隔开

x_{1} = \frac{- ( - 7 ) + 11}{2 ( - 1 )}, x_{2} = \frac{- ( - 7 ) - 11}{2 ( - 1 )}

x = \frac{- ( - 7 ) + 11}{2 ( - 1 )} : - 9

x = \frac{- ( - 7 ) - 11}{2 ( - 1 )} : 2

二次方程组的解是:

x = - 9, x = 2

作图

流行的例子

x^2+10x+25/2 =0

x^{2} + 10 x + \frac{25}{2} = 0

t^{2} = 5 t - 6

2808.8=0.68*2.14*100*x*(9.5-0.4*x)

2808.8 = 0.68 \cdot 2.14 \cdot 100 \cdot x \cdot (9.5 - 0.4 \cdot x)

2x^2-2x+3=x^2-3x+2

2 x^{2} - 2 x + 3 = x^{2} - 3 x + 2

solvefor x,2x^2+2xy+y^2=2

so l v e f or x, 2 x^{2} + 2 x y + y^{2} = 2