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-5)(40-x)=4(45-x)

解答

(x - 5) (40 - x) = 4 (45 - x)

解答

x = \frac{49 - 881}{2}, x = \frac{49 + 881}{2}

+1

十进制

x = 9.65917 \dots, x = 39.34082 \dots

求解步骤

(x - 5) (40 - x) = 4 (45 - x)

展开

(x - 5) (40 - x) : 45 x - x^{2} - 200

展开

4 (45 - x) : 180 - 4 x

45 x - x^{2} - 200 = 180 - 4 x

将

4 x

para o lado esquerdo

- x^{2} + 49 x - 200 = 180

将

180

para o lado esquerdo

- x^{2} + 49 x - 380 = 0

使用求根公式求解

x_{1, 2} = \frac{- 49 \pm 4 9 ^{2} - 4 ( - 1 ) ( - 380 )}{2 ( - 1 )}

4 9^{2} - 4 (- 1) (- 380) = 881

x_{1, 2} = \frac{- 49 \pm 881}{2 ( - 1 )}

将解分隔开

x_{1} = \frac{- 49 + 881}{2 ( - 1 )}, x_{2} = \frac{- 49 - 881}{2 ( - 1 )}

x = \frac{- 49 + 881}{2 ( - 1 )} : \frac{49 - 881}{2}

x = \frac{- 49 - 881}{2 ( - 1 )} : \frac{49 + 881}{2}

二次方程组的解是:

x = \frac{49 - 881}{2}, x = \frac{49 + 881}{2}

作图

流行的例子

12 z^{2} + 7 z - 10 = - 6

2(x^2-2x)+13=-7

2 (x^{2} - 2 x) + 13 = - 7

solvefor y,x=y-y^2

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

- 2 a \cdot 3 a = 25

x^{2} + 24 x + 102 = 0