\(a,=\left(27\dfrac{3}{49}-13\dfrac{3}{49}\right)-27\dfrac{9}{57}=14\dfrac{3}{49}-27\dfrac{9}{57}=\dfrac{689}{49}-\dfrac{516}{19}=-\dfrac{12193}{931}\\ b,=\left(3-5-6\right)+\left(\dfrac{7}{4}-\dfrac{1}{4}\right)+\left(\dfrac{2}{3}+\dfrac{1}{3}\right)+\left(\dfrac{6}{5}-\dfrac{3}{2}\right)\\ =-8+\dfrac{3}{2}+1-\dfrac{3}{10}=\dfrac{6}{5}-7=-\dfrac{29}{5}\\ c,=\dfrac{3}{5}\left(-\dfrac{3}{21}+\dfrac{1}{7}+1\right)=\dfrac{3}{5}\cdot1=\dfrac{3}{5}\\ d,=\dfrac{13}{16}\left(-\dfrac{17}{16}\cdot\dfrac{1}{2}-\dfrac{5}{16}-\dfrac{5}{32}\right)=\dfrac{13}{16}\left(-\dfrac{17}{32}-\dfrac{10}{32}-\dfrac{5}{32}\right)=\dfrac{13}{16}\cdot\left(-1\right)=-\dfrac{13}{16}\)
\(e,=\dfrac{14}{5}\cdot\dfrac{12}{7}\left(19\dfrac{5}{8}-13\dfrac{1}{4}\right)=\dfrac{24}{5}\left(\dfrac{157}{8}-\dfrac{106}{8}\right)=\dfrac{24}{5}\cdot\dfrac{51}{8}=\dfrac{153}{5}\\ f,=\left(2\dfrac{3}{7}-1\dfrac{3}{7}\right)+\dfrac{2}{9}-\dfrac{5}{3}\cdot9=1\dfrac{3}{7}-\dfrac{13}{9}=\dfrac{10}{7}-\dfrac{13}{9}=-\dfrac{1}{63}\)
