a: \(A=\left(-\frac25+\frac{3}{10}\right):\left(-\frac25+\left|-\frac43-2\right|\right)\)
\(=\left(-\frac{4}{10}+\frac{3}{10}\right):\left(-\frac25+\left|-\frac{10}{3}\right|\right)\)
\(=\frac{-1}{10}:\left(-\frac25+\frac{10}{3}\right)=-\frac{1}{10}:\left(-\frac{6}{15}+\frac{50}{15}\right)=-\frac{1}{10}:\frac{44}{15}\)
\(=-\frac{1}{10}\cdot\frac{15}{44}=\frac{-15}{440}=\frac{-3}{88}\)
b: \(B=\left|-\frac23+\frac32\right|\left(-\frac45-\left|-\frac32-1\right|\right)\)
\(=\left|-\frac46+\frac96\right|:\left(-\frac45-\frac52\right)=\frac56:\left(-\frac{8}{10}-\frac{25}{10}\right)=\frac56:\frac{-33}{10}\)
\(=\frac56\cdot\frac{10}{-33}=\frac{50}{-198}=\frac{-25}{99}\)
c: \(C=\left|-3\left(-\frac{13}{15}-\frac{17}{21}\right)\right|-\left|-\frac{13}{5}+\frac{17}{7}\right|+\left(-12+\frac{35}{3}\right):\left|-\frac76\right|\)
\(=\left|\frac{13}{5}+\frac{17}{7}\right|-\left(\frac{13}{5}-\frac{17}{7}\right)+\left(-\frac13\right):\frac76\)
\(=\frac{13}{5}+\frac{17}{7}-\frac{13}{5}+\frac{17}{7}+\left(-\frac13\right)\cdot\frac67=\frac{34}{7}-\frac27=\frac{32}{7}\)
