a, x( x - 3) - ( x + 2)( x - 1) = 3

<=> x² - 3x - x² + x - 2x + 2 = 3

<=>  x² - 3x - x² + x - 2x = 3 - 2

<=> -4x = 1

<=> x =\(-\frac{1}{4}\)

Vậy_

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

\(\Leftrightarrow\frac{30x}{30}-\frac{\left(x-1\right)6}{30}+\frac{\left(x+2\right)5}{30}=\frac{120}{30}+\frac{\left(x+1\right)10}{30}\)

=> 30x - 6x + 6 + 5x + 10 = 120 + 10x + 10

<=> 30x - 6x + 5x - 10x = 120 + 10 - 6 - 10

<=> 19x = 114

<=> x = 6

Vậy _

a ) \(\left|x-2\right|=2\)

       \(\Rightarrow\orbr{\begin{cases}x-2=2\\x-2=-2\end{cases}}\)

        \(\Rightarrow\orbr{\begin{cases}x=2+2\\x=-2+2\end{cases}}\)

       \(\Rightarrow\orbr{\begin{cases}x=4\\x=0\end{cases}}\) 

Vậy \(x=4\) hoặc \(x=0\)

b ) \(\left|x-\frac{4}{5}\right|=\frac{3}{4}\)

      \(\Rightarrow\orbr{\begin{cases}x-\frac{4}{5}=\frac{3}{4}\\x-\frac{4}{5}=-\frac{3}{4}\end{cases}}\)

       \(\Rightarrow\orbr{\begin{cases}x=\frac{3}{4}+\frac{4}{5}\\x=-\frac{3}{4}+\frac{4}{5}\end{cases}}\)

       \(\Rightarrow\orbr{\begin{cases}x=\frac{15}{20}+\frac{16}{20}\\-\frac{15}{20}+\frac{16}{20}\end{cases}}\)

         \(\Rightarrow\orbr{\begin{cases}x=\frac{31}{20}\\x=\frac{1}{20}\end{cases}}\)

Vậy \(x=\frac{31}{20}\) hoặc \(x=\frac{1}{20}\)

c ) \(6-\left|\frac{1}{2}-x\right|=\frac{2}{5}\)

                 \(\left|\frac{1}{2}-x\right|=6-\frac{2}{5}\)

              \(\left|\frac{1}{2}-x\right|=\frac{28}{5}\)

 \(\Rightarrow\orbr{\begin{cases}\frac{1}{2}-x=\frac{28}{5}\\\frac{1}{2}-x=-\frac{28}{5}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{1}{2}-\frac{28}{5}\\x=\frac{1}{2}-\left(-\frac{28}{5}\right)\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-\frac{51}{10}\\x=\frac{61}{10}\end{cases}}\)

Vậy \(x=-\frac{51}{10}\) hoặc \(x=\frac{61}{10}\)

d ) \(\frac{1}{5}-\left|\frac{1}{5}.x\right|=\frac{1}{5}\)

                   \(\left|\frac{1}{5}.x\right|=\frac{1}{5}-\frac{1}{5}\)

                    \(\left|\frac{1}{5}.x\right|=0\)

\(\Rightarrow\frac{1}{5}.x=0\)

               \(x=0:\frac{1}{5}\)

                \(x=0\)

Vậy \(x=0\)

e ) \(-2,5+\left|3x+5\right|=-1,5\)

                        \(\left|3x+5\right|=-1,5-\left(-2,5\right)\)

                       \(\left|3x+5\right|=1\)

\(\Rightarrow\orbr{\begin{cases}3x+5=1\\3x+5=-1\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}3x=1-5\\3x=-1-5\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}3x=-4\\3x=-6\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-4:3\\x=-6:3\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-\frac{4}{3}\\x=-2\end{cases}}\)

Vậy \(x=-\frac{4}{3}\) hoặc \(x=-2\)

g ) \(\left(\frac{2}{3}x-1\right)+\left(\frac{3}{4}x+\frac{1}{2}\right)=0\)

\(\Rightarrow\orbr{\begin{cases}\left(\frac{2}{3}x-1\right)=0\\\left(\frac{3}{4}x+\frac{1}{2}\right)=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}\frac{2}{3}x-1=0\\\frac{3}{4}x+\frac{1}{2}=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}\frac{2}{3}x=0+1\\\frac{3}{4}x=0-\frac{1}{2}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}\frac{2}{3}x=1\\\frac{3}{4}x=-\frac{1}{2}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=1:\frac{2}{3}\\x=-\frac{1}{2}:\frac{3}{4}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{3}{2}\\x=-\frac{2}{3}\end{cases}}\)

Vậy \(x=\frac{3}{2};x=-\frac{2}{3}\)

Bạn bạn hơi dài nhưng đã xong 

Chúc bạn học tốt !!!

Trả lời:

a, | x - 2 | = 2

=> x - 2 = 2 hoặc x - 2 = -2

=>    x = 4                x = 0

Vậy x = 4; x = 0

b, \(\left|x-\frac{4}{5}\right|=\frac{3}{4}\)

\(\Rightarrow x-\frac{4}{5}=\frac{3}{4}\)hoặc \(x-\frac{4}{5}=\frac{-3}{4}\)

\(\Rightarrow x=\frac{31}{20}\)hoặc \(x=\frac{1}{20}\)

Vậy \(x=\frac{31}{20};x=\frac{1}{20}\)

c, \(6-\left|\frac{1}{2}-x\right|=\frac{2}{5}\)

\(\Rightarrow\left|\frac{1}{2}-x\right|=\frac{28}{5}\)

\(\Rightarrow\frac{1}{2}-x=\frac{28}{5}\)hoặc \(\frac{1}{2}-x=\frac{-28}{5}\)

\(\Rightarrow x=\frac{-51}{10}\)hoặc \(x=\frac{61}{10}\)

Vậy \(x=\frac{-51}{10};x=\frac{61}{10}\)

d, \(\frac{1}{5}-\left|\frac{1}{5}\cdot x\right|=\frac{1}{5}\)

\(\Rightarrow\left|\frac{1}{5}\cdot x\right|=0\)

\(\Rightarrow\frac{1}{5}\cdot x=0\)

\(\Rightarrow x=0\)

Vậy x = 0
e, \(-2,5+\left|3x+5\right|=-1,5\)

\(\Rightarrow\left|3x+5\right|=1\)

\(\Rightarrow3x+5=1\)hoặc \(3x+5=-1\)

\(\Rightarrow3x=-4\)hoặc \(3x=-6\)

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

Vậy \(x=\frac{-4}{3};x=-2\)

g, \(\left(\frac{2}{3}x-1\right)+\left(\frac{3}{4}x+\frac{1}{2}\right)=0\)

\(\Rightarrow\frac{2}{3}x-1+\frac{3}{4}x+\frac{1}{2}=0\)

\(\Rightarrow\frac{17}{12}x-\frac{1}{2}=0\)

\(\Rightarrow\frac{17}{12}x=\frac{1}{2}\)

\(\Rightarrow x=\frac{6}{17}\)

Vậy \(x=\frac{6}{17}\)

a) \(\frac{3}{4}+\frac{1}{4}.x=\frac{1}{2}+\frac{1}{2}x\)

\(\Rightarrow3.\frac{1}{4}+\frac{1}{4}.x=\frac{1}{2}.\left(x+1\right)\)

\(\Rightarrow\frac{1}{4}.\left(x+3\right)=\frac{1}{2}.\left(x+1\right)\)

\(\Rightarrow\frac{x+1}{x+3}=\frac{1}{4}:\frac{1}{2}=\frac{1}{2}\)\(\Rightarrow\left(x+1\right).2=x+3\Rightarrow2x+2=x+3\)

\(\Rightarrow2x-x=3-2\Rightarrow x=1\)

vay x=1

(15/4.4-12/5.5/4)-(7/2:5/2-1/5)-1/5.x=51/5

(15-3)-(7/5-1/5)-1/5.x=51/5

12-6/5-1/5.x=51/5

54/5-1/5.x=51/5

        1/5x=54/5-51/5

         1/5x=3/5

             x=3

Bài 2 :

1) \(x-70=-45\) 2) \(\frac{4}{7}:x=\frac{12}{28}\)

\(\Rightarrow\) \(x=-45+70\) \(\Rightarrow x=\frac{4}{7}:\frac{12}{28}\)

\(\Rightarrow\) \(x=25\) \(\Rightarrow x=\frac{4}{3}\)

Vậy \(x=25\) Vậy \(x=\frac{4}{3}\)

3) Giống câu c) ở bài 1

4) \(x-50=-35\) 5) \(\frac{4}{7}.x=\frac{11}{18}\)

\(\Rightarrow x=-35+50\) \(\Rightarrow x=\frac{11}{28}:\frac{4}{7}\)

\(\Rightarrow x=15\) \(\Rightarrow x=\frac{77}{72}\)

Vậy \(x=15\) Vậy \(x=\frac{77}{72}\)

6) \(\left(\frac{2}{3}x+2,5\right):2\frac{2}{6}=6\)

\(\Rightarrow\)\(\left(\frac{2}{3}x+2,5\right):\frac{14}{6}=6\)

\(\Rightarrow\) \(\frac{2}{3}x+2,5=6.\frac{14}{6}\)

\(\Rightarrow\frac{2}{3}x+2,5=14\)

\(\Rightarrow\frac{2}{3}x=\frac{23}{2}\)

\(\Rightarrow x=\frac{23}{2}:\frac{2}{3}\)

\(\Rightarrow x=\frac{69}{4}\)

Vậy \(x=\frac{69}{4}\)

Bài 1:

1) \(\frac{7}{5}+\frac{-8}{5}=-\frac{1}{5}\)

2) \(-\frac{6}{5}.\frac{15}{24}=-\frac{3}{4}\)

3) \(\left(\frac{2}{3}+1,5\right)-3,5:7\frac{1}{2}=\)\(\frac{13}{6}-\frac{7}{15}=\frac{17}{10}\)

4) \(\frac{5}{8}-\frac{-7}{9}=\frac{5}{8}+\frac{7}{9}=\frac{101}{72}\)

5)\(\frac{-7}{3}.\frac{12}{28}=-1\)

a, 3/4 + 1/4.x=2

    1/4.x        = 2-3/4

     1/4.x      =5/4

     x           = 5/4:1/4

     x           = 5

b, x-2/3.9/4=2,5-1/2

    x-2/3.9/4=2

    x-2/3     =2:9/4

    x-2/3   =8/9

     x        = 8/9+2/3

     x         = 14/9

c, 2.x+1/3=4/3

    2.x      =4/3-1/3

    2.x      =1

       x      =11:2

       x      = 1/2

a ) \(\left(\frac{2}{5}-x\right):1\frac{1}{3}+\frac{1}{2}=-4\)

     \(\left(\frac{2}{5}-x\right):\frac{4}{3}+\frac{1}{2}=-4\)

     \(\left(\frac{2}{5}-x\right):\frac{4}{3}=-4-\frac{1}{2}\)

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

        \(\frac{2}{5}-x=-\frac{9}{2}.\frac{4}{3}\)

        \(\frac{2}{5}-x=-3\)

                   \(x=\frac{2}{5}-\left(-3\right)\)

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

                   \(x=\frac{3}{5}-\frac{15}{5}\)

                   \(x=-\frac{12}{5}\)

Vay \(x=-\frac{12}{5}\) 

b ) \(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\left(1+\frac{2}{5}+\frac{2}{3}\right)=-\frac{5}{4}\)

     \(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\left(\frac{15}{15}+\frac{6}{15}+\frac{10}{15}\right)=-\frac{5}{4}\)

     \(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\left(\frac{15+6+10}{15}\right)=-\frac{5}{4}\)

     \(\left(-3+\frac{3}{x}-\frac{1}{3}\right):\frac{31}{15}=-\frac{5}{4}\)

     \(\left(-3+\frac{3}{x}-\frac{1}{3}\right)=-\frac{5}{4}.\frac{31}{15}\)

     \(\left(-3+\frac{3}{x}-\frac{1}{3}\right)=-\frac{1}{4}.\frac{31}{3}\)

        \(-3+\frac{3}{x}-\frac{1}{3}=-\frac{31}{12}\)

        \(-3+\frac{3}{x}=-\frac{31}{12}+\frac{1}{2}\)

        \(-3+\frac{3}{x}=-\frac{31}{12}+\frac{6}{12}\)

        \(-3+\frac{3}{x}=\frac{-25}{12}\)

                     \(\frac{3}{x}=\frac{-25}{12}+3\)

                      \(\frac{3}{x}=\frac{-25}{12}+\frac{36}{12}\)

                      \(\frac{3}{x}=\frac{5}{6}\)

                      \(\frac{18}{6x}=\frac{5x}{6x}\)

Đèn dây , bạn tự làm tiếp nhé , de rồi chứ

Ta có : \(\left(5x-3\right)\left(2x+5\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}5x-3=0\\2x+5=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}5x=3\\2x=-5\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=\frac{3}{5}\\x=-\frac{5}{2}\end{cases}}\)