\(\Rightarrow\left(\frac{7}{3}:x-\frac{2}{3}\right):\frac{7}{4}=-\frac{17}{5}-\frac{10}{9}\Rightarrow\left(\frac{7}{3}:x-\frac{2}{3}\right):\frac{7}{4}=-\frac{203}{45}\Rightarrow\frac{7}{3}:x-\frac{2}{3}=-\frac{1421}{180}\Rightarrow\frac{7}{3}:x=-\frac{1301}{180}\Rightarrow x=-\frac{420}{1301}\)

\(x\times\frac{6}{25}=\frac{15}{-13}\)

x=\(\frac{15}{-13}\div\frac{6}{25}\)

x=\(-\frac{125}{26}\)

các câu còn lại làm tương tự nha!!!

\(1.x.\frac{6}{25}=\frac{15}{-13}\\ x=\frac{15}{-13}:\frac{6}{25}\\ x=-\frac{125}{26}\)

\(2.x:\frac{4}{10}=\frac{13}{-45}+\frac{8}{15}\\ x:\frac{4}{10}=\frac{11}{45}\\ x=\frac{11}{45}.\frac{4}{10}\\ x=\frac{22}{225}\)

\(3.\frac{3}{8}-\frac{1}{6}.x=\frac{1}{4}\\ \frac{1}{6}.x=\frac{3}{8}-\frac{1}{4}\\ \frac{1}{6}.x=\frac{1}{8}\\ x=\frac{1}{8}:\frac{1}{6}\\ x=\frac{3}{4}\)

\(4.\frac{1}{3}+\frac{1}{2}:x=-4\\ \frac{1}{2}:x=-4-\frac{1}{3}=-\frac{13}{3}\\ x=\frac{1}{2}:\left(-\frac{13}{3}\right)=-\frac{3}{26}\)

\(5.x+\frac{7}{12}=\frac{17}{18}-\frac{1}{9}=\frac{5}{6}\\ x=\frac{5}{6}-\frac{7}{12}\\ x=\frac{1}{4}\)

\(\frac{-5}{x}=\frac{-y}{8}=\frac{18}{72}\)

\(\Leftrightarrow\frac{-5}{x}=\frac{-y}{8}=\frac{1}{4}\)

\(\Leftrightarrow\orbr{\begin{cases}-\frac{5}{x}=\frac{1}{4}\\-\frac{y}{8}=\frac{1}{4}\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-5.4:1\\-y=8.1:4\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-20\\-y=2\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=-20\\y=-2\end{cases}}}\)

vậy x=-20 và y=-2

\(-\frac{1}{3}-x=\frac{1}{2}-\frac{1}{-4}\)

\(-\frac{1}{3}-x=\frac{1}{2}-\frac{-1}{4}\)

\(-\frac{1}{3}-x=\frac{2}{4}-\frac{-1}{4}\)

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

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

\(x=-\frac{4}{12}-\frac{9}{12}\)

\(x=-\frac{13}{12}\)

\(x=-\frac{18}{24}+\frac{15}{21}\)

\(x=-\frac{3}{4}+\frac{5}{7}\)

\(x=-\frac{21}{28}+\frac{20}{28}\)

\(x=-\frac{1}{28}\)

a/ \(\frac{15}{x}-\frac{1}{3}=\frac{28}{51}\)

\(\frac{15}{x}=\frac{28}{51}+\frac{1}{3}\)

\(\frac{15}{x}=\frac{15}{17}\)

\(x=15:\frac{15}{17}\)

\(x=17\)

b) \(\frac{x}{20}-\frac{2}{5}=10\)

\(\frac{x}{20}=10+\frac{2}{5}\)

\(\frac{x}{20}=\frac{52}{5}\)

\(x=\frac{52}{5}\cdot20\)

\(x=208\)

c) \(x+\frac{18}{23}=2\frac{1}{3}\)

\(x+\frac{18}{23}=\frac{7}{3}\)

\(x=\frac{7}{3}-\frac{18}{23}\)

\(x=\frac{107}{69}\)

d) \(\frac{7}{11}< x-\frac{1}{7}< \frac{10}{13}\)

\(\Rightarrow\frac{7}{11}+\frac{1}{7}< x< \frac{10}{13}\)

\(\frac{60}{77}< x< \frac{60}{78}\)

Đến đây .....bí!

e) Tớ bỏ luôn đc ko.

D) 7/11<X-1/7<10/13

    <=> 7/11+1/7<x< 10/13+1/7

 <=> 60/77< x< 83/91

<=> 5460/1001 <x< 6391/1001

vậy X thuộc tập hợp các phÂN số lớn hơn 5460/1001 và bé hơn 913/1001

vd :  Y/1001 trong đó y là 5461;5462;5463...6389;6390

e) 7/9<13/11-x<15/16

<=> 7/9-13/11<-x< 15/16 -13/11

<=> -40/99< -x< -43/176

<=> 43/99< x < 40/176( nhân với -1 nên đổi dấu )

<=> 387/1584 < x< 640/1584

<=> vậy X là các phân số có dạng y/1584 , trong đó Y là 388;389;390 ........ 639

.a, \(\frac{x+1}{999}+\frac{x+2}{998}=\frac{x+3}{997}+\frac{x+4}{996}\)

.\(< =>\frac{x+1}{999}+1+\frac{x+2}{998}+1=\frac{x+3}{997}+1+\frac{x+4}{996}+1\)

.\(< =>\frac{x+1}{999}+\frac{999}{999}+\frac{x+2}{998}+\frac{998}{998}=\frac{x+3}{997}+\frac{997}{997}+\frac{x+4}{996}+\frac{996}{996}\)

.\(< =>\frac{x+1+999}{999}+\frac{x+2+998}{998}=\frac{x+3+997}{997}+\frac{x+4+996}{996}\)

.\(< =>\frac{x+1000}{999}+\frac{x+1000}{998}-\frac{x+1000}{997}-\frac{x+1000}{996}=0\)

.\(< =>\left(x+1000\right)\left(\frac{1}{999}+\frac{1}{998}-\frac{1}{997}-\frac{1}{996}\right)=0\)

.Do \(\frac{1}{999}+\frac{1}{998}-\frac{1}{997}-\frac{1}{996}\ne0\)

.Suy ra \(x+1000=0\Leftrightarrow x=-1000\)

.b, \(\frac{x+1}{1001}+\frac{x+2}{1002}=\frac{x+3}{1003}+\frac{x+4}{1004}\)

.\(< =>\frac{x+1}{1001}-1+\frac{x+2}{1002}-1=\frac{x+3}{1003}-1+\frac{x+4}{1004}-1\)

.\(< =>\frac{x+1}{1001}-\frac{1001}{1001}+\frac{x+2}{1002}-\frac{1002}{1002}=\frac{x+3}{1003}-\frac{1003}{1003}+\frac{x+4}{1004}-\frac{1004}{1004}\)

.\(< =>\frac{x+1-1001}{1001}+\frac{x+2-1002}{1002}=\frac{x+3-1003}{1003}+\frac{x+4-1004}{1004}\)

.\(< =>\frac{x-1000}{1001}+\frac{x+1000}{1002}-\frac{x+1000}{1003}-\frac{x+1000}{1004}=0\)

.\(< =>\left(x-1000\right)\left(\frac{1}{1001}+\frac{1}{1002}-\frac{1}{1003}-\frac{1}{1004}\right)=0\)

.Do \(\frac{1}{1001}+\frac{1}{1002}-\frac{1}{1003}-\frac{1}{1004}\ne0\)

.Suy ra \(x-1000=0\Leftrightarrow x=1000\)

cảm ơn

mình làm luộn 2 câu còn lại nhé ^^

.c,\(|x|-\frac{15}{2}=\frac{15}{4}\)

.\(< =>|x|=\frac{15}{4}+\frac{15}{2}=\frac{15}{4}+\frac{30}{4}=\frac{45}{4}\)

.\(< =>\orbr{\begin{cases}x=\frac{45}{4}\\x=-\frac{45}{4}\end{cases}}\)

.d,\(|\frac{3}{4}-x|+1=\frac{3}{2}\)

.\(< =>|\frac{3}{4}-x|=\frac{3}{2}-1=\frac{3}{2}-\frac{2}{2}=\frac{1}{2}\)

.\(< =>\orbr{\begin{cases}\frac{3}{4}-x=\frac{1}{2}\\\frac{3}{4}-x=-\frac{1}{2}\end{cases}< =>\orbr{\begin{cases}x=\frac{3}{4}-\frac{1}{2}=\frac{1}{4}\\x=\frac{3}{4}+\frac{1}{2}=\frac{5}{4}\end{cases}}}\)