Đáp án:

 $A=\dfrac{-3}{88}\\
B=\dfrac{-13}{12}\\
C=\dfrac{32}{7}\\
D=\dfrac{-23}{25}$

Giải thích các bước giải:

 $A=\left ( -\dfrac{2}{5}+\dfrac{3}{10} \right ):\left ( \dfrac{2}{-5}+\left | -\dfrac{4}{3}-2 \right | \right )\\
=\left ( -\dfrac{4}{10}+\dfrac{3}{10} \right ):\left ( \dfrac{2}{-5}+\left | -\dfrac{4}{3}-\dfrac{6}{3} \right | \right )\\
=\dfrac{-1}{10}:\left ( \dfrac{-2}{5}+\left |\dfrac{-10}{3} \right | \right )\\
=\dfrac{-1}{10}:\left ( \dfrac{-2}{5}+\dfrac{10}{3} \right )\\
=\dfrac{-1}{10}:\left ( \dfrac{-6}{15}+\dfrac{50}{15} \right )\\
=\dfrac{-1}{10}:\dfrac{44}{15}\\
=\dfrac{-1}{10}.\dfrac{15}{44}=\dfrac{-3}{88}\\
B=\left | \dfrac{-2}{3}+\dfrac{3}{2} \right |\left ( \dfrac{-4}{5}-\left | -\dfrac{3}{-2}-1 \right | \right )\\
=\left | \dfrac{-4}{6}+\dfrac{9}{6} \right |\left ( \dfrac{-4}{5}-\left | \dfrac{3}{2}-\dfrac{2}{2} \right | \right )\\
= \dfrac{5}{6}\left ( \dfrac{-4}{5}-\dfrac{1}{2} \right )\\
=\dfrac{5}{6}\left ( \dfrac{-8}{10}-\dfrac{5}{10} \right )\\
=\dfrac{5}{6}.\dfrac{-13}{10}\\
=\dfrac{-13}{12}\\
C=\left | -3\left ( -\dfrac{13}{15}-\dfrac{17}{21} \right ) \right |-\left | -\dfrac{13}{5}+\dfrac{17}{7} \right |+\left ( -12+\dfrac{35}{3} \right ):\left | -\dfrac{7}{6} \right |\\
=\left | -3\left ( -\dfrac{91}{105}-\dfrac{85}{105} \right ) \right |-\left | -\dfrac{91}{35}+\dfrac{85}{35} \right |+\left ( \dfrac{-36}{3}+\dfrac{35}{3} \right ):\dfrac{7}{6} \\
=\left | -3.\dfrac{-176}{105} \right |-\dfrac{6}{35}+ \dfrac{-1}{3}:\dfrac{7}{6} \\
=\dfrac{176}{35}-\dfrac{6}{35}-\dfrac{1}{3}.\dfrac{6}{7}\\
=\dfrac{170}{35}-\dfrac{2}{7}\\
=\dfrac{34}{7}-\dfrac{2}{7}=\dfrac{32}{7}\\
D=\dfrac{-\dfrac{2}{3}+\dfrac{3}{4}-2}{\dfrac{2}{3}-\dfrac{3}{4}-2}.\dfrac{\dfrac{-2}{3}-\dfrac{3}{4}-2}{\dfrac{2}{3}+\dfrac{3}{4}+2}\\
=\dfrac{-\left (\dfrac{2}{3}-\dfrac{3}{4}+2  \right )}{\dfrac{2}{3}-\dfrac{3}{4}-2}.\dfrac{-\left (\dfrac{2}{3}+\dfrac{3}{4}+2  \right )}{\dfrac{2}{3}+\dfrac{3}{4}+2}\\
=\dfrac{\dfrac{2}{3}-\dfrac{3}{4}+2}{\dfrac{2}{3}-\dfrac{3}{4}-2}\\
=\dfrac{\dfrac{8}{12}-\dfrac{9}{12}+\dfrac{24}{12}}{\dfrac{8}{12}-\dfrac{9}{12}-\dfrac{24}{2}}\\
=\dfrac{\dfrac{23}{12}}{\dfrac{-25}{12}}\\
=\dfrac{-23}{25}$