\(\frac{36}{\left(1-7x\right)}=\frac{\left(1-7x\right)}{49}\)

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a) Ta có: \(5x\left(\frac{1}{5}x-2\right)+3\left(6-\frac{1}{3}x^2\right)=12\)

\(\Leftrightarrow x^2-10x+18-x^2=12\)

\(\Leftrightarrow-10x+18=12\)

\(\Leftrightarrow-10x=-6\)

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

Vậy: \(x=\frac{3}{5}\)

b) Ta có: \(7x\left(x-2\right)-5\left(x-1\right)=7x^2+3\)

\(\Leftrightarrow7x^2-14x-5x+5-7x^2-3=0\)

\(\Leftrightarrow-19x+2=0\)

\(\Leftrightarrow-19x=-2\)

hay \(x=\frac{2}{19}\)

Vậy: \(x=\frac{2}{19}\)

20 tháng 7 2016

a) (5x + 1)= 36/49

     (5x + 1)= (6/7)2

suy ra: 5x + 1= 6/7               hoặc         5x +1 = -6/7

                 5x    = 6/7 - 1                               5x  = -6/7 -1

                 5x   = -1/7                                    5x   = -13/7

                   x    =  -1/7 : 5                               x   = -13/7 : 5

                   x   = -1/35                                   x     = -13/35

20 tháng 7 2016

a,   \(\left(5x+1\right)^2=\frac{36}{49}\)
\(\left(5x+1\right)^2=\left(\frac{6}{7}\right)^2\)
=> 5x + 1 = \(\frac{6}{7}\)
\(\Rightarrow5x=\frac{6}{7}-1\)
\(\Rightarrow5x=\frac{-1}{7}\)
\(\Rightarrow x=\frac{-1}{7}:5=\frac{-1}{35}\)
b,,   \(\left(2x-\frac{1}{2}\right)^2=\frac{1}{4}\)
\(\left(2x-\frac{1}{2}\right)^2=\left(\frac{1}{2}\right)^2\)
\(\Rightarrow2x-\frac{1}{2}=\frac{1}{2}\)
\(\Rightarrow2x=\frac{1}{2}+\frac{1}{2}=1\)
\(\Rightarrow x=1:2=\frac{1}{2}\)

16 tháng 8 2017

a) \(\left(2x-3\right)^2=36\)

\(\left(2x-3\right)^2=6^2\)

\(2x-3=6\)

\(2x=9\)

\(x=4,5\)

b) \(\left(2x-1\right)^5=243\)

\(\left(2x-1\right)^5=3^5\)

\(2x-1=3\)

\(2x=4\)

\(x=2\)

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

 

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

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

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

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

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

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

 

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

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

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

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

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