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 >

12-{6x+[3x+(x-7)(x+7)]-(2x+3)^2}=-2x^2+5[(x+1)^2-3(x+6)]

解答

12 - {6 x + [3 x + (x - 7) (x + 7)] - (2 x + 3)^{2}} = - 2 x^{2} + 5 [(x + 1)^{2} - 3 (x + 6)]

解答

x = - \frac{155}{8}

+1

十进制

x = - 19.375

求解步骤

12 - {6 x + [3 x + (x - 7) (x + 7)] - (2 x + 3)^{2}} = - 2 x^{2} + 5 [(x + 1)^{2} - 3 (x + 6)]

去除括号:

(a) = a

12 - (6 x + 3 x + (x - 7) (x + 7) - (2 x + 3)^{2}) = - 2 x^{2} + 5 [(x + 1)^{2} - 3 (x + 6)]

同类项相加:

6 x + 3 x = 9 x

12 - (9 x + (x - 7) (x + 7) - (2 x + 3)^{2}) = - 2 x^{2} + 5 [(x + 1)^{2} - 3 (x + 6)]

展开

12 - (9 x + (x - 7) (x + 7) - (2 x + 3)^{2}) : 3 x^{2} + 3 x + 70

展开

- 2 x^{2} + 5 ((x + 1)^{2} - 3 (x + 6)) : 3 x^{2} - 5 x - 85

3 x^{2} + 3 x + 70 = 3 x^{2} - 5 x - 85

将

70

到右边

3 x^{2} + 3 x = 3 x^{2} - 5 x - 155

两边减去

3 x^{2} - 5 x

3 x^{2} + 3 x - (3 x^{2} - 5 x) = 3 x^{2} - 5 x - 155 - (3 x^{2} - 5 x)

化简

8 x = - 155

两边除以

8

x = - \frac{155}{8}

作图

流行的例子

solvefor x,4x+8y=20

so l v e f or x, 4 x + 8 y = 20

6 - x = 5 x + 30

(2/3+5/3)^2=(2/3)^2+(5/3)^2

(\frac{2}{3} + \frac{5}{3})^{2} = (\frac{2}{3})^{2} + (\frac{5}{3})^{2}

-7(-5k+10)+1=10+6k+8

- 7 (- 5 k + 10) + 1 = 10 + 6 k + 8

\frac{1}{5} x + 4 = 6 - 2 x