a

\(5\frac{4}{7}:x+=13\)

\(\frac{39}{7}:x=13\)

\(x=\frac{39}{7}:13\)

\(x=\frac{3}{7}\)

\(\frac{4}{7}x=\frac{9}{8}-0,125\)

\(\frac{4}{7}x=1\)

\(x=1:\frac{4}{7}\)

\(x=\frac{7}{4}=1\frac{3}{4}\)

a) = 3/3 x ( -24/54 +45/54 ) : 7/12

   = 1 x 21/54 x 12/7

   = 18/27 

( hiện tại mik chỉ lm đc thế này thui. thông cảm nk )

\(\frac{4}{3}.\left(\frac{1}{6}-\frac{1}{2}\right)< x< \frac{2}{3}.\left(\frac{-1}{6}+\frac{3}{4}\right)\)

⇒ \(\frac{4}{3}.\left(\frac{-1}{3}\right)< x< \frac{2}{3}.\left(\frac{7}{12}\right)\)

⇒ \(\frac{-4}{9}< x< \frac{7}{18}\)

⇒ \(\frac{-8}{18}< x< \frac{7}{18}\)

mà -8<x<7

⇒ x ϵ \(\left\{-7;-6;-5;-4;....;5;6\right\}\)

Bài 2: 

b: x+25%x=-1,25

=>1,25x=-1,25

hay x=-1

c: x-75%x=1/4

=>1/4x=1/4

hay x=1

Bài 2: 

a: =3/2-11/4=6/4-11/4=-5/4

b: =-49/6-17/2=-49/6-51/6=-100/6=-50/3

a) x=\(\frac{-9}{10}\)

b)x=-6

Dạng này rất đơn giản, bạn nhìn các câu hỏi trước của bạn mà làm.

Ta có ; \(\left(x+\frac{1}{2}\right)^2=\frac{4}{25}\)

\(\Leftrightarrow\left(x+\frac{1}{2}\right)^2=\left(\frac{2}{5}\right)^2\)

\(\Rightarrow x+\frac{1}{2}=\frac{2}{5}\)

\(\Rightarrow x=\frac{2}{5}-\frac{1}{2}=-\frac{1}{10}\)

\(x:(3\frac{1}{2}-5\frac{1}{6})=4\frac{1}{5}-6\frac{2}{3}\)                           b,\((2\frac{1}{3}+3\frac{1}{2})\cdot x=-4\frac{1}{4}+3\frac{1}{7}\)

\(x:\frac{-5}{3}\)=\(\frac{-37}{15}\)                                                              \(\frac{35}{6}\cdot x=\)\(\frac{-31}{28}\)

\(x=\frac{-37}{15}\cdot\frac{-5}{3}\)                                                              \(x=\frac{-31}{28}:\)\(\frac{35}{6}\)

\(x=\frac{37}{9}\)                                                                              \(x=\frac{-93}{490}\)

Vậy x=\(\frac{37}{9}\)                                                                           Vậy x=\(\frac{-93}{490}\)

7,5x:\((9-6\frac{13}{21})=2\frac{13}{25}\)

7,5x:\(\frac{50}{21}\)=\(\frac{63}{25}\)

7,5x=\(\frac{63}{25}:\frac{50}{21}=\frac{1323}{1250}\)

x=\(\frac{1323}{1250}:7,5\)

x=\(\frac{441}{3125}\)

Vậy x=\(\frac{441}{3125}\)

a) \(\frac{x}{3}-\frac{1}{4}=\frac{-5}{6}\)

\(\Rightarrow\frac{x}{3}=\frac{-5}{6}+\frac{1}{4}\)

\(\Rightarrow\frac{x}{3}=\frac{-7}{12}\)

\(\Rightarrow x=\frac{\left(-7\right).3}{12}\)

\(\Rightarrow x=\frac{-7}{4}\)

Vậy x = \(\frac{-7}{4}\)

b) \(\frac{x+3}{15}=\frac{1}{3}\)

\(\Rightarrow\left(x+3\right).3=15\)

\(\Rightarrow x+3=15:3\)

\(\Rightarrow x+3=5\)

\(\Rightarrow x=5-3\)

\(\Rightarrow x=2\)

Vậy x = 2

c) \(\frac{x-12}{4}=\frac{1}{2}\)

\(\Rightarrow\left(x-12\right).2=4\)

\(\Rightarrow x-12=4:2\)

\(\Rightarrow x-12=2\)

\(\Rightarrow x=2+12\)

\(\Rightarrow x=14\)

Vậy x = 14

d) \(\frac{25}{9}-\frac{12}{13}x=\frac{7}{9}\)

\(\Rightarrow\frac{12}{13}x=\frac{25}{9}-\frac{7}{9}\)

\(\Rightarrow\frac{12}{13}x=2\)

\(\Rightarrow x=2:\frac{12}{13}\)

\(\Rightarrow x=\frac{13}{6}\)

Vậy x = \(\frac{13}{6}\)

_Chúc bạn học tốt_

a)\(\frac{x}{3}-\frac{1}{4}=-\frac{5}{6}\)

\(\frac{x}{3}=-\frac{5}{6}+\frac{1}{4}\)

\(\frac{x}{3}=-\frac{7}{12}\)

\(x=-\frac{7}{12}\times3\)

\(\Rightarrow x=-\frac{7}{4}\)

b) \(\frac{x+3}{15}=\frac{1}{3}\)

\(\frac{x+3}{15\div5}=\frac{1}{3}\)

\(\Rightarrow x=5-3\)

\(\Rightarrow x=2\)

c) \(\frac{x-12}{4}=\frac{1}{2}\)

\(\frac{x-12}{4\div2}=\frac{1}{2}\)

\(x=12+2\)

\(\Rightarrow x=14\)

d) tự làm nhé cũng dễ mà

\(\frac{2}{3}x-\frac{1}{2}=\frac{1}{10}\)

\(\frac{2}{3}x\)            = \(\frac{1}{10}+\frac{1}{2}\)

\(\frac{2}{3}x\)            =          \(\frac{3}{5}\)

     \(x\)             =     \(\frac{3}{5}:\frac{2}{3}\)

     \(x\)             =         \(\frac{9}{10}\)

Câu b:

(2 4/5x - 50) : 2/3 = 51

2 4/5x - 50 = 51 x 2/3

14/5x - 50 = 34

14/5x = 34 + 50

14/5x = 84

x = 84 : 14/5

x = 30

Vậy x = 30