Đáp án:

 $1)
x=\dfrac{-1}{4}\\
2)
x=\dfrac{3}{7}\\
3)
x=-1\\
4)
 x=6\\
5)
x=\dfrac{-5}{7}\\
6)
 x=\dfrac{13}{12}\\
7)
x=\dfrac{15}{16}\\
8)
 x=\dfrac{13}{28}\\
9)
x=\dfrac{-3}{20}\\
10)
 x=\dfrac{-5}{12}\\
11)
 x=\dfrac{10}{3}\\
12)
 x=\dfrac{21}{10}\\
13)
x=\dfrac{13}{2}\\
14)
x=-9\\
15)
 x=-1\\
16)
 x=\{-3,-2,-1,0\}$

Giải thích các bước giải:

 $1)
-\dfrac{2}{5}x+\dfrac{1}{5}=\dfrac{3}{10}\\
\Leftrightarrow -\dfrac{2}{5}x=\dfrac{3}{10}-\dfrac{1}{5}\\
\Leftrightarrow -\dfrac{2}{5}x=\dfrac{3}{10}-\dfrac{2}{10}\\
\Leftrightarrow -\dfrac{2}{5}x=\dfrac{1}{10}\\
\Leftrightarrow x=\dfrac{1}{10}.\dfrac{-5}{2}=\dfrac{-1}{4}\\
2)
5\dfrac{4}{7}:x=13\\
\Leftrightarrow \dfrac{39}{7}.\dfrac{1}{x}=13\\
\Leftrightarrow \dfrac{1}{x}=13.\dfrac{7}{39}=\dfrac{7}{3}\\
\Leftrightarrow x=\dfrac{3}{7}\\
3)
\dfrac{-2}{3}-x=\dfrac{4}{12}\\
\Leftrightarrow x=\dfrac{-2}{3}-\dfrac{4}{12}\\
\Leftrightarrow x=\dfrac{-8}{12}-\dfrac{4}{12}\\
\Leftrightarrow x=\dfrac{-12}{12}=-1\\
4)
\dfrac{2}{3}x-\dfrac{1}{2}x=1\\
\Leftrightarrow \left ( \dfrac{2}{3}-\dfrac{1}{2} \right )x=1\\
\Leftrightarrow \left ( \dfrac{4}{6}-\dfrac{3}{6} \right )x=1\\
\Leftrightarrow \dfrac{1}{6}x=1\\
\Leftrightarrow x=6\\
5)
\dfrac{-3}{5}x=\dfrac{3}{7}\\
\Leftrightarrow x=\dfrac{3}{7}.\dfrac{-5}{3}=\dfrac{-5}{7}\\
6)
\dfrac{3}{4}+x=\dfrac{11}{6}\\
\Leftrightarrow x=\dfrac{11}{6}-\dfrac{3}{4}\\
\Leftrightarrow x=\dfrac{22}{12}-\dfrac{9}{12}\\
\Leftrightarrow x=\dfrac{13}{12}\\
7)
\dfrac{2}{3}x+\dfrac{2}{5}x=1\\
\Leftrightarrow \left ( \dfrac{2}{3}+\dfrac{2}{5} \right )x=1\\
\Leftrightarrow \left ( \dfrac{10}{15}+\dfrac{6}{15} \right )x=1\\
\Leftrightarrow \dfrac{16}{15}x=1\\
\Leftrightarrow x=\dfrac{15}{16}\\
8)
\dfrac{2}{7}+x=0,75\\
\Leftrightarrow x=\dfrac{3}{4}-\dfrac{2}{7}\\
\Leftrightarrow x=\dfrac{21}{28}-\dfrac{8}{28}\\
\Leftrightarrow x=\dfrac{13}{28}\\
9)
\dfrac{1}{5}-\dfrac{2}{3}x=\dfrac{3}{10}\\
\Leftrightarrow \dfrac{2}{3}x=\dfrac{1}{5}-\dfrac{3}{10}\\
\Leftrightarrow \dfrac{2}{3}x=\dfrac{2}{10}-\dfrac{3}{10}\\
\Leftrightarrow \dfrac{2}{3}x=\dfrac{-1}{10}\\
\Leftrightarrow x=\dfrac{-1}{10}.\dfrac{3}{2}=\dfrac{-3}{20}\\
10)
x-\dfrac{3}{4}=\dfrac{-7}{6}\\
\Leftrightarrow x=\dfrac{-7}{6}+\dfrac{3}{4}\\
\Leftrightarrow x=\dfrac{-14}{12}+\dfrac{9}{12}\\
\Leftrightarrow x=\dfrac{-5}{12}\\
11)
\dfrac{x}{5}=\dfrac{2}{3}\\
\Leftrightarrow x=\dfrac{2}{3}.5\\
\Leftrightarrow x=\dfrac{10}{3}\\
12)
\dfrac{x}{3}-\dfrac{1}{2}=\dfrac{1}{5}\\
\Leftrightarrow \dfrac{x}{3}=\dfrac{1}{5}+\dfrac{1}{2}\\
\Leftrightarrow \dfrac{x}{3}=\dfrac{2}{10}+\dfrac{5}{10}\\
\Leftrightarrow \dfrac{x}{3}=\dfrac{7}{10}\\
\Leftrightarrow x=\dfrac{21}{10}\\
13)
\dfrac{x+1}{2}=\dfrac{15}{4}\\
\Leftrightarrow x+1=\dfrac{15}{2}\\
\Leftrightarrow x=\dfrac{15}{2}-1\\
\Leftrightarrow x=\dfrac{15}{2}-\dfrac{2}{2}=\dfrac{13}{2}\\
14)
3\dfrac{1}{3}x+16\dfrac{3}{4}=-13,25\\
\Leftrightarrow \dfrac{10}{3}x+\dfrac{67}{4}=-\dfrac{1325}{100}\\
\Leftrightarrow \dfrac{10}{3}x=-\dfrac{53}{4}-\dfrac{67}{4}\\
\Leftrightarrow \dfrac{10}{3}x=-\dfrac{120}{4}\\
\Leftrightarrow x=-30.\dfrac{3}{10}=-9\\
15)
\left ( 1\dfrac{1}{3}-\dfrac{25}{100}-\dfrac{5}{6} \right )-2x=\dfrac{9}{4}\\
\Leftrightarrow \dfrac{4}{3}-\dfrac{1}{4}-\dfrac{5}{6} -2x=\dfrac{9}{4}\\
\Leftrightarrow 2x=\dfrac{4}{3}-\dfrac{1}{4}-\dfrac{5}{6}-\dfrac{9}{4}\\
\Leftrightarrow 2x=\dfrac{4}{3}-\dfrac{5}{6}-\dfrac{10}{4}\\
\Leftrightarrow 2x=\dfrac{16}{12}-\dfrac{10}{12}-\dfrac{30}{12}\\
\Leftrightarrow 2x=\dfrac{-24}{12}=-2\\
\Leftrightarrow x=-1\\
16)
\dfrac{-2}{3}<\dfrac{x}{6}<\dfrac{1}{6}\\
\Leftrightarrow \dfrac{-2}{3}.6<x<6.\dfrac{1}{6}\\
\Leftrightarrow -4<x<1\\
\Rightarrow x=\{-3,-2,-1,0\}$