g; \(\dfrac{1}{3}\)\(x\) + \(\dfrac{2}{5}\).(\(x-1\)) = 0

    \(\dfrac{1}{3}x+\dfrac{2}{5}x\) - \(\dfrac{2}{5}\) = 0

    \(\dfrac{11}{15}\)\(x\)     - \(\dfrac{2}{5}\)  = 0

      \(\dfrac{11}{15}x\)           = \(\dfrac{2}{5}\)

           \(x\)           = \(\dfrac{2}{5}\) : \(\dfrac{11}{15}\)

            \(x\)         = \(\dfrac{6}{11}\)

Vậy \(x\) = \(\dfrac{6}{11}\) 

f; (\(x+\dfrac{1}{2}\)).(\(\dfrac{2}{3}\) - 2\(x\)) = 0

  \(\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\)

   \(\left[{}\begin{matrix}x=-\dfrac{1}{2}\\2x=\dfrac{2}{3}\end{matrix}\right.\)

     \(\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{2}{3}:2\end{matrix}\right.\)

      \(\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)
Vậy \(x\) \(\in\) {\(-\dfrac{1}{2}\); \(\dfrac{1}{3}\)}

e; \(\dfrac{5}{4}x\) - \(\dfrac{1}{5}.\)\(\dfrac{5}{2}\) = \(\dfrac{1}{3}\): (- \(\dfrac{1}{6}\))

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

     \(\dfrac{5}{4}x\)          = - 2 + \(\dfrac{1}{2}\)

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

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

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

Vậy \(x\) = - \(\dfrac{6}{5}\) 

d; - \(\dfrac{1}{3}\) + \(\dfrac{5}{2}\)\(x\) = \(\dfrac{1}{6}\) : (- \(\dfrac{2}{9}\))

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

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

             \(\dfrac{5}{2}\)\(x\) = - \(\dfrac{5}{12}\)

                 \(x\) = - \(\dfrac{5}{12}\) : \(\dfrac{5}{2}\)

                 \(x\) = - \(\dfrac{1}{6}\)

Vậy \(x\) = - \(\dfrac{1}{6}\)

c; (\(\dfrac{1}{3}\) - \(x\)) : \(\dfrac{3}{4}\) + \(\dfrac{1}{4}\) = - \(\dfrac{2}{3}\)

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

    (\(\dfrac{1}{3}\) - \(x\)) : \(\dfrac{3}{4}\)        = - \(\dfrac{11}{12}\)

     \(\dfrac{1}{3}\) - \(x\)              = - \(\dfrac{11}{12}\) x \(\dfrac{3}{4}\)

      \(\dfrac{1}{3}\) - \(x\)            = - \(\dfrac{11}{16}\)

             \(x\)            =  \(\dfrac{1}{3}\) + \(\dfrac{11}{16}\)

              \(x\)           = \(\dfrac{49}{48}\)

Vậy \(x\) = \(\dfrac{49}{48}\) 

Bài 3:

a; \(\dfrac{-4}{9}\) - 2\(x\) = \(\dfrac{5}{-12}\) - \(\dfrac{-5}{9}\)

    \(\dfrac{-4}{9}\) - 2\(x\) = \(\dfrac{5}{36}\)

            2\(x\) = \(\dfrac{-4}{9}\) - \(\dfrac{5}{36}\)

            2\(x\) = - \(\dfrac{7}{12}\)

              \(x\) = - \(\dfrac{7}{12}\) : 2

               \(x\) = - \(\dfrac{7}{24}\)

Vậy \(x\) = - \(\dfrac{7}{24}\)

b; \(\dfrac{1}{2}\)(\(x\) + 2) + \(\dfrac{3}{8}\) = \(\dfrac{7}{16}\)

    \(\dfrac{1}{2}\)\(x\) + 1 + \(\dfrac{3}{8}\) = \(\dfrac{7}{16}\)

     \(\dfrac{1}{2}x\)  + \(\dfrac{11}{8}\)     = \(\dfrac{7}{16}\)

       \(\dfrac{1}{2}\)\(x\)              = \(\dfrac{7}{16}\) - \(\dfrac{11}{8}\)

        \(\dfrac{1}{2}x\)            = - \(\dfrac{15}{16}\)

           \(x\)           = - \(\dfrac{15}{16}\) \(\times\) 2

           \(x\)          = - \(\dfrac{15}{8}\)

Vậy \(x\) = - \(\dfrac{15}{8}\) 

Bài 4:

Bài 3: b

Bài 3:

a; 

Hình Học 

Bài 1: b

a M \(\in\) a; N \(\notin\) a