1/4+1/3:(2x-1)=-5

-->1/3:(2x-1)=-5-1/4

-->1/3:(2x-1)=-21/4

-->2x-1        =1/3:-21/4

-->2x-1        =-4/63

-->2x           =-4/63+1

-->2x           =59/63

--x               =59/126

b7/9:(2+3/4x)+5/9=23/27

-->7/9:(2+3/4x)     =23/27-5/9

-->7/9:(2+3/4x)     =8/27

-->2+3/4x             =7/9:8/27

-->2+3/4x             =21/8

-->3/4x                 =21/8-2

-->3/4x                 =5/8

-->x                     =5/8:3/4

-->x                     =5/6

c|2x-1/3|+5/6=1

-->|2x-1/3|    =1-5/6

-->|2x-1/3|    =1/6

-->\(\orbr{\begin{cases}2x-\frac{1}{3}=\frac{1}{6}\\2x-\frac{1}{3}=-\frac{1}{6}\end{cases}}\)

-->\(\orbr{\begin{cases}2x=\frac{1}{6}+\frac{1}{3}\\2x=-\frac{1}{6}+\frac{1}{3}\end{cases}}\)

-->\(\orbr{\begin{cases}2x=\frac{1}{2}\\2x=\frac{1}{6}\end{cases}}\)

-->\(\orbr{\begin{cases}x=\frac{1}{2}:2\\x=\frac{1}{6}:2\end{cases}}\)

-->\(\orbr{\begin{cases}x=\frac{1}{4}\\x=\frac{1}{12}\end{cases}}\)

MF MAF:

\(\frac{7}{9}:\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)

\(\frac{7}{9}:\left(2+\frac{3}{4}x\right)=\frac{23}{27}-\frac{5}{9}\)

\(\frac{7}{9}:\left(2+\frac{3}{4}x\right)=\frac{23}{27}-\frac{15}{27}\)

        \(\left(2+\frac{3}{4}x\right)=\frac{7}{9}:\frac{8}{27}\)

                    \(\frac{3}{4}x=\frac{21}{8}-\frac{16}{8}\)  

                     \(\frac{3}{4}x=\frac{5}{8}\)              

                            \(x=\frac{5}{8}:\frac{3}{4}\)

                            \(x=\frac{5}{6}\)

Vậy x = 5/6

Tham khảo nha ~~

lớp 5 hả bạn

2: \(=\dfrac{-2}{75}+\dfrac{5}{39}=\dfrac{33}{325}\)

3: \(=\dfrac{6}{11}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{6}{11}\)

4: \(=\dfrac{7}{19}\left(\dfrac{5}{13}+\dfrac{8}{13}-1\right)=-2\cdot\dfrac{7}{19}=-\dfrac{14}{19}\)

5: \(=\dfrac{2}{7}\left(\dfrac{4}{23}-\dfrac{27}{23}+1\right)=0\)

6: \(=\dfrac{3}{8}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)+\dfrac{11}{8}=\dfrac{3}{8}+\dfrac{11}{8}=\dfrac{14}{8}=\dfrac{7}{4}\)

đấy nhá

b) Ta có: \(\left|x\right|-\dfrac{3}{4}=\dfrac{5}{3}\)

\(\Leftrightarrow\left|x\right|=\dfrac{5}{3}+\dfrac{3}{4}=\dfrac{20}{12}+\dfrac{9}{12}=\dfrac{29}{12}\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{29}{12}\\x=-\dfrac{29}{12}\end{matrix}\right.\)

c) Ta có: \(\left|2x-\dfrac{1}{3}\right|+\dfrac{5}{6}=1\)

\(\Leftrightarrow\left|2x-\dfrac{1}{3}\right|=\dfrac{1}{6}\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-\dfrac{1}{3}=\dfrac{1}{6}\\2x-\dfrac{1}{3}=\dfrac{-1}{6}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=\dfrac{1}{6}+\dfrac{1}{3}=\dfrac{1}{2}\\2x=\dfrac{1}{6}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{4}\\x=\dfrac{1}{12}\end{matrix}\right.\)

Mấy bài này bình thường mà bạn ! Bạn áp dụng tính chất phân phối 

7/9:(2+3/4x)=23/27-5/9

7/9:(2+3/4x)=23/27-15/27

7/9:(2+3/4x)=8/27

2+3/4x=7/9:8/27

2+3/4x=21/8

3/4x=21/8-2

3/4x=21/8-16/8

3/4x=5/8

x=5/8:3/4

x=5/6

Một đ ú n g nha..............

1.

a) \(\frac{-7}{9}.2\frac{3}{4}=\frac{-7}{9}.\frac{11}{4}=\frac{-77}{36}\)

b) \(\frac{2}{3}+\frac{1}{3}.\frac{-2}{5}=\frac{2}{3}+\frac{-2}{15}=\frac{8}{15}\)

c) \(\frac{3}{4}.15\frac{1}{3}-\frac{3}{4}.43\frac{1}{3}=\frac{3}{4}.\frac{46}{3}-\frac{3}{4}.\frac{130}{3}=\frac{23}{2}-\frac{65}{2}=-21\)

d) \(\left(-49,1\right).\frac{13}{27}-58,9.\frac{13}{27}=\frac{13}{27}.\left(-49,1-58,9\right)=\frac{13}{27}.\left(-108\right)=-52\)

e) \(0,375:\left(-4,5\right)=\frac{-1}{12}\)

f) \(3\frac{1}{7}:\left(-1\frac{3}{7}\right)=\frac{22}{7}:\frac{-10}{7}=\frac{-11}{5}\)

g) \(9\frac{1}{3}:4\frac{2}{3}-2=\frac{28}{3}:\frac{14}{3}-2=2-2=0\)

h) \(\left(7\frac{3}{4}:0,3125+4,5.2\frac{2}{45}\right):\left(-8,5\right)=\left(\frac{31}{4}:\frac{5}{16}+\frac{9}{2}.\frac{92}{45}\right):\frac{-17}{2}=\left(\frac{124}{5}+\frac{46}{5}\right):\frac{-17}{2}=34:\frac{-17}{2}=-4\)

Bài 1 : Tính:

a)

\(\frac{-7}{9}.2\frac{3}{4}=\frac{-7}{9}.\frac{11}{4}=\frac{-77}{36}\)

b) 

\(\frac{2}{3}+\frac{1}{3}.\frac{-2}{5}=\frac{2}{3}+\frac{-2}{15}=\frac{10}{15}+\frac{-2}{15}=\frac{8}{15}\)

c)

\(\frac{3}{4}.15\frac{1}{3}-\frac{3}{4}.43\frac{1}{3}=\frac{3}{4}.\frac{46}{3}-\frac{3}{4}.\frac{130}{3}\)\(=\frac{23}{2}-\frac{65}{2}=\frac{-42}{2}=-21\)

....

Tự lm tiếp dạng như v

Bài 2 : 

\(A=\frac{-6}{11}.\frac{7}{10}.\frac{11}{-6}.-20=\left(\frac{-6}{11}.\frac{11}{-6}\right).\left(\frac{7}{10}.-20\right)\)\(=1.\left(-14\right)=-14\)

.....

Bài 3 : 

\(\frac{3}{7}.x-\frac{2}{5}.x=\frac{-17}{35}\)

\(\Leftrightarrow\frac{3}{7}-\frac{2}{5}.x=\frac{-17}{35}\)

\(\Leftrightarrow\frac{1}{35}x=\frac{-17}{35}\)

\(\Leftrightarrow x=\frac{-17}{35}:\frac{1}{35}\)

\(\Leftrightarrow x=\frac{-17}{35}.35=-17\)