Question

[Lê Thanh Thúy]

Bài 1 : Tìm x biết

a) \(13\frac{1}{3}\div1\frac{1}{3}=26\div\left(2x-1\right)\)

b) \(0,2:1\frac{1}{5}=\frac{2}{3}\div\left(6x+7\right)\)

c) \(\frac{37-x}{x+13}=\frac{3}{7}\)

d) \(\frac{x-1}{x+5}=\frac{6}{7}\)

e) \(2\frac{2}{\frac{3}{0,002}=}\frac{1\frac{1}{9}}{x}\)

Bài 2 : Tìm x,y,z biết:

a) \(\frac{x}{7}=\frac{4}{13}\)và x + y = 40

b) 3x = 2y , 7y = 57 và x - y + z = 32

c) \(\frac{x-1}{2}=\frac{y-2}{3}=\frac{7-4}{4}\)và 2x + 3y - z = 50
Bài 3 .

a) 6,88 : x =12:27

b) \(8\frac{1}{3}\div11\frac{2}{3}=13:\left(2x\right)\)

Giải giúp mk

Mk đng cần gấp

Answer 1

[Lê Thanh Nhàn]

1.

a) 13\(\frac{1}{3}\) : 1\(\frac{1}{3}\) = 26 : (2x - 1)

<=> \(\frac{40}{3}:\frac{4}{3}\) = 13x - 26

<=> 10 + 26 = 13x

<=> 13x = 36

<=> x = \(\frac{36}{13}\)

b) 0,2 : 1\(\frac{1}{5}\) = \(\frac{2}{3}\) : (6x + 7)

<=> \(\frac{1}{5}:\frac{6}{5}\) = \(\frac{1}{9}x\) : \(\frac{2}{21}\)

<=> \(\frac{1}{6}\) = \(\frac{1}{9}x\) : \(\frac{2}{21}\)

<=> \(\frac{1}{9}x\) = \(\frac{2}{21}.\frac{1}{6}\) = \(\frac{1}{63}\)

<=> x = \(\frac{1}{7}\)

c) \(\frac{37-x}{x+13}\) = \(\frac{3}{7}\)

<=> (37 - x) . 7 = 3.(x + 13)

<=> 119 - 7x = 3x + 39

<=> -7x - 3x = 39 - 119

<=> -10x = -80

<=> x = 8

d) \(\frac{x-1}{x+5}=\frac{6}{7}\)

<=> 7(x - 1) = 6(x + 5)

<=> 7x - 7 = 6x + 30

<=> 7x - 6x = 30 + 7

<=> x = 37

e)

2\(\frac{2}{\frac{3}{0,002}}\) = \(\frac{1\frac{1}{9}}{x}\)

<=> \(\frac{1501}{750}\) = \(\frac{10}{9}:x\)

<=> x = \(\frac{10}{9}:\frac{1501}{750}\) = \(\frac{2500}{4503}\)

Answer 2

[Lê Thanh Nhàn]

Bài 2. đề sai

Bài 3.

a) 6,88 : x = \(\frac{12}{27}\)

<=> x = 6,88 : \(\frac{12}{27}\)

<=> x = 15,48

b) 8\(\frac{1}{3}\) : \(11\frac{2}{3}\) = 13 : 2x

<=> \(\frac{25}{3}:\frac{35}{3}\) = 13 : 2x

<=> \(\frac{5}{7}=13:2x\)

<=> 2x = \(13:\frac{5}{7}\) = \(\frac{91}{5}\)

<=> x = 9,1