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3 tháng 10 2018

\(x=\frac{35}{108}\)

3 tháng 10 2018

Ta có

\(2\left(\frac{3}{2}-x\right)-\frac{1}{3}=7x-\frac{1}{4}\)

\(\Leftrightarrow3-2x-\frac{1}{3}=7x-\frac{1}{4}\)

\(\Leftrightarrow9x-\frac{1}{4}=\frac{8}{3}\)

\(\Leftrightarrow9x=\frac{8}{3}+\frac{1}{4}=\frac{35}{12}\)

\(\Leftrightarrow x=\frac{35}{108}\)

6 tháng 8 2015

Bạn xem ở đây nè: http://olm.vn/hoi-dap/question/158643.html

31 tháng 1 2016

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

=> \(\frac{6}{4}-10x=\frac{4}{5}-3x\)

=>\(-10x+3x=\frac{4}{5}-\frac{6}{4}\)

=> \(x=\frac{1}{10}\)

2 .

\(\frac{3}{2}-4\left(\frac{1}{4}-x\right)=\frac{2}{3}-7x\)

=>\(\frac{3}{2}-1+4x=\frac{2}{3}-7x\)

=>\(11x=\frac{1}{6}\)

=>x=\(\frac{1}{66}\)

3.

\(3\left(\frac{1}{2}-x\right)+\frac{1}{3}=\frac{7}{6}-x\)

=>\(\frac{3}{2}-3x+\frac{1}{3}=\frac{7}{6}-x\)

=>\(-2x=\frac{-2}{3}\)

=>\(\frac{1}{3}\)

4. câu 4 ko hiểu bạn ơi

 

6 tháng 8 2015

hj các cậu làm câu nào cx được hết á

6 tháng 8 2015

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

\(\Leftrightarrow-\frac{3}{2}\cdot\frac{2}{15}+x=4x-\frac{8}{3}\)

\(\Leftrightarrow-\frac{1}{5}+x=4x-\frac{8}{3}\)

\(\Leftrightarrow x-4x=-\frac{8}{3}+\frac{1}{5}\)

\(\Leftrightarrow-3x=-\frac{37}{15}\)

\(\Leftrightarrow x=\frac{37}{45}\)

 

2)\(2\left(\frac{3}{2}-x\right)-\frac{1}{3}=7x-\frac{1}{4}\)

\(\Leftrightarrow3-2x-\frac{1}{3}=7x-\frac{1}{4}\)

\(\Leftrightarrow-2x-7x=-\frac{1}{4}-3+\frac{1}{3}\)

\(\Leftrightarrow-9x=-\frac{35}{12}\)

\(\Leftrightarrow x=\frac{35}{108}\)

 

3)\(\frac{1}{5}\left(-\frac{3}{5}10\right)+5x=x-\frac{2}{3}\)

\(\Leftrightarrow-\frac{6}{5}+5x=x-\frac{2}{3}\)

\(\Leftrightarrow5x-x=-\frac{2}{3}+\frac{6}{5}\)

\(\Leftrightarrow4x=\frac{8}{15}\)

\(\Leftrightarrow x=\frac{2}{15}\)

 

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

\(\Leftrightarrow-\frac{15}{2}+\frac{1}{4}+4x-2=1\)

\(\Leftrightarrow4x=1+\frac{15}{2}-\frac{1}{4}+2\)

\(\Leftrightarrow4x=\frac{41}{4}\)

\(\Leftrightarrow x=\frac{41}{16}\)

khỏi chép lại đề ha

  • 2 - 4x - 5x + \(\frac{3}{2}\)= \(\frac{7}{4}\)

          \(\frac{7}{2}\)- 9x = \(\frac{7}{4}\)

           -9x = \(\frac{7}{2}-\frac{7}{4}\)

           -9x = \(\frac{7}{4}\)

            x = \(\frac{7}{4}:\left(-9\right)\)

            x = \(\frac{-7}{36}\)

  • 3 - 2x - \(\frac{1}{3}=7x-\frac{1}{4}\)

          -2x - 7x = \(\frac{-1}{4}-3+\frac{1}{3}\)

         -9x = \(\frac{-35}{12}\)

          x = \(\frac{-35}{12}:\left(-9\right)\)

          x = \(\frac{35}{108}\)

  • \(\frac{-15}{2}\)+ \(\frac{1}{4}\)+ 4x -2 = 1

            4x = 1 + \(\frac{15}{2}-\frac{1}{4}+2\)

            4x = \(\frac{41}{4}\)

            x = \(\frac{41}{4}:4\)

            x = \(\frac{41}{16}\)

6 tháng 8 2015

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

\(\frac{6}{4}-10x=\frac{4}{5}-3x\)

\(\frac{6}{4}+\frac{4}{5}=7x\)

\(\frac{23}{10}=7x\)

\(\frac{23}{70}=x\)

2,\(\frac{3}{2}-4\left(\frac{1}{4}-x\right)=\frac{2}{3}-7x\)

\(\frac{3}{2}-1-4x=\frac{2}{3}-7x\)

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

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

\(\frac{1}{18}=x\)

3,\(3\left(\frac{1}{2}-x\right)+\frac{1}{3}=\frac{7}{6}-x\)

\(\frac{3}{2}-3x+\frac{1}{3}=\frac{7}{6}-x\)

\(\frac{3}{2}-\frac{7}{6}+\frac{1}{3}=2x\)

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

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

4,mình không hiểu a ở đây là gì

 

 

 

18 tháng 5 2016

1) \(x=\frac{99}{196}\)

2) \(x=-2\)

3) \(x\approx-0,59\)

giup mk giải rõ dc ko

15 tháng 6 2016

\(x-\frac{\frac{x}{2}-\frac{3+x}{4}}{2}=\frac{2x-\frac{10-7x}{3}}{2}-\left(x+1\right)\)

 

<=>\(2x-\frac{x}{2}+\frac{3+x}{4}=2x-\frac{10-7x}{3}-2\left(x+1\right)\)

<=>\(24x-6x+9+3x=24x-40+28x-24x-24\)

<=>\(21x+9=28x-64\)

<=>\(-7x=-73\)

<=>x=73/7

 

HQ
Hà Quang Minh
Giáo viên
19 tháng 9 2023

a)

\(\begin{array}{l}\frac{2}{9}:x + \frac{5}{6} = 0,5\\\frac{2}{9}:x = \frac{1}{2} - \frac{5}{6}\\\frac{2}{9}:x = \frac{3}{6} - \frac{5}{6}\\\frac{2}{9}:x = \frac{{ - 2}}{6}\\x = \frac{2}{9}:\frac{{ - 2}}{6}\\x = \frac{2}{9}.\frac{{ - 6}}{2}\\x = \frac{{ - 2}}{3}\end{array}\)                        

Vậy \(x = \frac{{ - 2}}{3}\).

b)

\(\begin{array}{l}\frac{3}{4} - \left( {x - \frac{2}{3}} \right) = 1\frac{1}{3}\\x - \frac{2}{3} = \frac{3}{4} - 1\frac{1}{3}\\x - \frac{2}{3} = \frac{3}{4} - \frac{4}{3}\\x - \frac{2}{3} = \frac{9}{{12}} - \frac{{16}}{{12}}\\x - \frac{2}{3} = \frac{{ - 7}}{{12}}\\x = \frac{{ - 7}}{{12}} + \frac{2}{3}\\x = \frac{{ - 7}}{{12}} + \frac{8}{{12}}\\x = \frac{1}{12}\end{array}\)

Vậy\(x = \frac{1}{12}\).

c)

\(\begin{array}{l}1\frac{1}{4}:\left( {x - \frac{2}{3}} \right) = 0,75\\\frac{5}{4}:\left( {x - \frac{2}{3}} \right) = \frac{3}{4}\\x - \frac{2}{3} = \frac{5}{4}:\frac{3}{4}\\x - \frac{2}{3} = \frac{5}{4}.\frac{4}{3}\\x - \frac{2}{3} = \frac{5}{3}\\x = \frac{5}{3} + \frac{2}{3}\\x = \frac{7}{3}\end{array}\)               

Vậy \(x = \frac{7}{3}\).

d)

\(\begin{array}{l}\left( { - \frac{5}{6}x + \frac{5}{4}} \right):\frac{3}{2} = \frac{4}{3}\\ - \frac{5}{6}x + \frac{5}{4} = \frac{4}{3}.\frac{3}{2}\\ - \frac{5}{6}x + \frac{5}{4} = 2\\ - \frac{5}{6}x = 2 - \frac{5}{4}\\ - \frac{5}{6}x = \frac{8}{4} - \frac{5}{4}\\ - \frac{5}{6}x = \frac{3}{4}\\x = \frac{3}{4}:\left( { - \frac{5}{6}} \right)\\x = \frac{3}{4}.\frac{{ - 6}}{5}\\x = \frac{{ - 9}}{{10}}\end{array}\)

Vậy \(x = \frac{{ - 9}}{{10}}\).

\(\Leftrightarrow\dfrac{1}{2}x^2-3x-\dfrac{9}{2}-\dfrac{4}{3}\left(x^2+4x+4\right)-\dfrac{5}{4}\left(x^2-1\right)=\dfrac{3}{2}x\left(x-2\right)-x-4\)

\(\Leftrightarrow\dfrac{1}{2}x^2-3x-\dfrac{9}{2}-\dfrac{4}{3}x^2-\dfrac{16}{3}x-\dfrac{16}{3}-\dfrac{5}{4}x^2+\dfrac{5}{4}=\dfrac{3}{2}x^2-3x-x-4\)

\(\Leftrightarrow x^2\cdot\dfrac{-25}{12}-\dfrac{25}{3}x-\dfrac{103}{12}-\dfrac{3}{2}x^2+4x+4=0\)

\(\Leftrightarrow\dfrac{-43x^2}{12x}-\dfrac{13x}{3}-\dfrac{55}{12}=0\)

\(\Leftrightarrow43x^2+52x+55=0\)

\(\text{Δ}=52^2-4\cdot43\cdot55=-6756< 0\)

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