( 5,5.x - 44 : - 3/2 = 30

=> 5,5.x - 44 = 30. - 3/2

 5,5.x - 44 =- 45

=> 5,5.x = ( - 45 )+44

5,5 .x =  - 1

x =- 1 : 5,5

x =- 2/11

(5,5x-44):(-\(\frac{3}{2}\))=30

5,5x-44          =30.(\(-\frac{3}{2}\))=-45

5,5x               =-45+44=-1

    x                =-1:5,5=\(-\frac{2}{11}\)

\(a.-8:\left(4\dfrac{1}{5}x+\dfrac{3}{10}\right)=4\dfrac{4}{9}\)

\(4\dfrac{1}{5}x+\dfrac{3}{10}=\left(-8\right):4\dfrac{4}{9}\)

\(4\dfrac{1}{5}x+\dfrac{3}{10}=\dfrac{-9}{5}\)

\(4\dfrac{1}{5}x=\dfrac{-9}{5}-\dfrac{3}{10}\)

\(4\dfrac{1}{5}x=\dfrac{-21}{10}\)

\(x=\dfrac{-21}{10}:\dfrac{21}{5}\)

\(x=\dfrac{-1}{2}\)

Vay \(x=\dfrac{-1}{2}\).

\(b.4\dfrac{2}{3}-\left(\dfrac{3}{5}:x\right)=-20\%\)

\(\dfrac{14}{3}-\left(\dfrac{3}{5}:x\right)=\dfrac{-1}{5}\)

\(\dfrac{3}{5}:x=\dfrac{14}{3}-\dfrac{-1}{5}\)

\(\dfrac{3}{5}:x=\dfrac{73}{15}\)

\(x=\dfrac{3}{5}:\dfrac{73}{15}\)

\(x=\dfrac{9}{73}\)

Vay \(x=\dfrac{9}{73}\).

Câu c; d; e tương tự nhé.

a: =>3/2x=64/15

=>x=128/45

b: =>-1/6x=7/12

=>x=-7/2

c: =>11/2*x=1/2

=>x=1/2:11/2=1/11

\(\frac{4}{\frac{2}{5}}:\left(-\frac{33}{10}\right)+x=-\frac{1}{\frac{5}{6}}\)

\(10:\left(-\frac{33}{10}\right)+x=-\frac{6}{5}\)

\(-\frac{100}{33}+x=-\frac{6}{5}\)

\(x=\frac{302}{165}\)

a) \(0,5x-\dfrac{2}{3}x=\dfrac{7}{12}\)

\(\dfrac{1}{2}x-\dfrac{2}{3}x=\dfrac{7}{12}\)

\(\left(\dfrac{1}{2}-\dfrac{2}{3}\right)x=\dfrac{7}{12}\)

\(\dfrac{-1}{6}x=\dfrac{7}{12}\)

\(x=\dfrac{7}{12}:\dfrac{-1}{6}\)

\(x=\dfrac{-7}{2}\)

b) \(x:4\dfrac{1}{3}=-2,5\)

\(x:\dfrac{13}{3}=\dfrac{-5}{2}\)

\(x=\dfrac{13}{3}.\dfrac{-5}{2}\)

\(x=\dfrac{-65}{6}\)

c) \(5,5x=\dfrac{13}{15}\)

\(\dfrac{11}{2}x=\dfrac{13}{15}\)

\(x=\dfrac{13}{15}:\dfrac{11}{2}\)

\(x=\dfrac{26}{165}\)

d) \(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)

\(\left(\dfrac{3x}{7}+1\right)=\dfrac{-1}{28}.\left(-4\right)\)

\(\dfrac{3x}{7}+1=\dfrac{1}{7}\)

\(\dfrac{3x}{7}=\dfrac{1}{7}-1\)

\(\dfrac{3x}{7}=\dfrac{-6}{7}\)

\(\Rightarrow3x=-6\\ x=\left(-6\right):3\\ x=-2\)

câu d mình nhầm bạn nha

d)\(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)

\(\dfrac{3x}{7}+1=\dfrac{-1}{28}.\left(-4\right)\)

\(\left(\dfrac{3x}{7}+1\right)=\dfrac{1}{7}\)

\(\dfrac{3x}{7}=\dfrac{1}{7}-1\)

\(\dfrac{3x}{7}=\dfrac{-6}{7}\)

Ta có : 3x =-6

x = -6:3

x=-2

a) 0,5x-\(\dfrac{2}{3}x=\dfrac{7}{12}\)

x\(\left(\dfrac{1}{2}-\dfrac{2}{3}\right)=\dfrac{7}{12}\)

\(\dfrac{-1}{6}x=\dfrac{7}{12}\)

x = \(\dfrac{7}{12}:\dfrac{-1}{6}\)

x =\(\dfrac{-7}{2}\)

b)\(x:4\dfrac{1}{3}=-2,5\)

\(x:\dfrac{13}{3}=\dfrac{-25}{10}\)

\(x=\dfrac{-5}{2}:\dfrac{13}{3}\)

\(x=\dfrac{-15}{26}\)

c)5,5\(x\)=\(\dfrac{13}{15}\)

\(\dfrac{11}{2}\)\(x\)=\(\dfrac{13}{15}\)

\(x=\dfrac{13}{15}:\dfrac{11}{2}\)

\(x=\dfrac{26}{165}\)

d)\(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)

\(\dfrac{3x}{7}+1\)=\(\dfrac{-1}{28}:\left(-4\right)\)

\(\left(\dfrac{3x}{7}+1\right)=\dfrac{1}{112}\)

\(\dfrac{3x}{7}=\dfrac{1}{112}-1\)

\(\dfrac{3x}{7}=\dfrac{-111}{112}\)

ta có 3x.112=-111.7

3x.112=-777

Vì -777 \(⋮̸̸\)112

\(\Rightarrow\) Bài sai

a: \(\dfrac{-13}{40}< \dfrac{-12}{40}\)

\(\dfrac{-5}{6}>\dfrac{-91}{104}\)

Sao bn giống BT mình thế ?:)

Đặt \(\dfrac{x}{-3}=\dfrac{y}{-8}=k\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=3k\\y=8k\end{matrix}\right.\)

Ta có: \(x^2-y^2=-\dfrac{44}{5}\)

\(\Leftrightarrow9k^2-64k^2=-\dfrac{44}{5}\)

\(\Leftrightarrow k^2=\dfrac{4}{25}\)

Trường hợp 1: \(k=\dfrac{2}{5}\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=3k=\dfrac{6}{5}\\y=8k=\dfrac{16}{5}\end{matrix}\right.\)

Trường hợp 2: \(k=-\dfrac{2}{5}\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=3k=\dfrac{-6}{5}\\y=8k=\dfrac{-16}{5}\end{matrix}\right.\)

C

Chọn C

\(\dfrac{5}{9}:x=\dfrac{40}{45}-\dfrac{9}{45}\)

\(\dfrac{5}{9}:x=\dfrac{31}{45}\)

\(x=\dfrac{5}{9}:\dfrac{31}{45}\)

\(x=\dfrac{225}{279}=\dfrac{25}{31}\)

`=>C`