x/5 + x2 + x/5:1/2=13

x/5 + x.2 + x/5 x 2 = 13

x/5.(1 + 2 ) + 2x = 13

x/5 .3 +2x = 13

3x/5 + 2x = 13

3x + 10x = 65

13x = 65

x = 65 : 13

x = 5

a) \(\frac{1}{2}+\frac{2}{3}x=\frac{4}{5}\)

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

\(x=\frac{9}{20}\)

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

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

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

\(\Rightarrow\hept{\begin{cases}x+\frac{3}{4}=\frac{1}{2}\\x+\frac{3}{4}=-\frac{1}{2}\end{cases}\Rightarrow\hept{\begin{cases}x=\frac{-1}{4}\\x=\frac{-5}{4}\end{cases}}}\)

Vậy x=-1/4 hoặc x=-5/4

c) \(\left(x+\frac{1}{3}\right)^3=\frac{-1}{8}\)

\(\Leftrightarrow x+\frac{1}{3}=\frac{-1}{8}=\frac{\left(-1\right)^3}{2^3}=\frac{-1}{2}\)

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

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

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

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

\(\frac{2}{3}x=\frac{3}{10}\)

\(x=\frac{3}{10}:\frac{2}{3}\)

\(x=\frac{9}{20}\)

b) l x + 3/4 l - 1/2 = 0

    l x + 3/4 l = 1/2

TH1 : \(x+\frac{3}{4}\le0\)                           TH2: \(x+\frac{3}{4}\ge0\)

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

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

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

c) ( x + 1/3 )³ = ( -1/8 )

( x + 1/3 ) ³ = ( -1/3 )³

=> x + 1/3 = -1/3

x = -1/3 - 1/3

x = -2/3

a) [ 2x ] = -1

=> 2x = 1

x = 1 : 2

x = 0,5

​b ) [ x + 0.4 ] = 3

=> [ x + 0 ] = 3

​=> x + 0 = 3 hoặc x + 0 = -3

​+) x + 0 = 3

x = 3 - 0

x = 3

​+) x + 0 = -3

x = ( -3 ) -0

x = -3

=> x thuộc { -3 ; 3 }

a) x = (-1) : 2 = -0,5

b) x = 3 - 0,4 = 2,6

c) x = (3 + 5) : 2/3 = 12 

a) \(\left(x+5\right)^2=100\Leftrightarrow\orbr{\begin{cases}\left(x+5\right)^2=10^2\\\left(x+5\right)^2=\left(-10\right)^2\end{cases}\Leftrightarrow\orbr{\begin{cases}x+5=10\\x+5=-10\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=5\\x=-15\end{cases}}}\)

b) \(\left(2x-4\right)^2=0\Leftrightarrow2x-4=0\Leftrightarrow2x=4\Leftrightarrow x=2\)

c) \(\left(x-1\right)^3=27\Leftrightarrow\left(x-1\right)^3=3^3\Leftrightarrow x-1=3\Leftrightarrow x=4\)

a) \(\left(x+5\right)^2=100\)

=> \(\orbr{\begin{cases}\left(x+5\right)^2=10^2\\\left(x+5\right)^2=\left(-10\right)^2\end{cases}}\)

=> \(\orbr{\begin{cases}x+5=10\\x+5=-10\end{cases}}\)

=> \(\orbr{\begin{cases}x=5\\x=-15\end{cases}}\)

b) \(\left(2x-4\right)^2=0\)

=> \(2x-4=0\)

=> \(2x=4\)

=> \(x=2\)

c) \(\left(x-1\right)^3=27\)

=> \(\left(x-1\right)^3=3^3\)

=> \(x-1=3\)

=> \(x=4\)

Cảm ơn các bn nha

3+(-2)+x=5

3-2+x=5

1+x=5

x=5-1

x=4

                      Vậy x=4

         tk cho mk nha!          

\(a\times5:6=25\)

\(a\times5=25\times6\)

\(a\times5=150\)

\(a=150:5\)

\(a=30\)

\(a\times5:6=25\\ a\times\dfrac{5}{6}=25\\ a=25:\dfrac{5}{6}\\ a=25\times\dfrac{6}{5}\\ a=30\)

a x 5 : 6 = 25

a x 5      = 25 x 6

a x 5      = 150

a            =150 : 5

a            = 30