\(a,\)
\(4-\dfrac{2}{3}-\dfrac{10}{24}=\dfrac{4}{1}-\dfrac{2}{3}-\dfrac{10}{24}=\dfrac{96}{24}-\dfrac{16}{24}-\dfrac{10}{24}=\dfrac{80}{24}-\dfrac{10}{24}=\dfrac{70}{24}=\dfrac{35}{12}\)
\(b,\)
\(\dfrac{12}{7}\times\dfrac{3}{4}\div\dfrac{3}{14}=\dfrac{12}{7}\times\dfrac{3}{4}\times\dfrac{14}{3}=\dfrac{12\times3\times14}{7\times4\times3}=\dfrac{6}{1}=6\)
\(c,\) \(2+\dfrac{5}{2}\div18=\dfrac{2}{1}+\dfrac{5}{2}\div\dfrac{18}{1}=\dfrac{2}{1}+\dfrac{5}{2}\times\dfrac{1}{18}=\dfrac{2}{1}+\dfrac{5}{36}=\dfrac{78}{36}+\dfrac{5}{36}=\dfrac{78+5}{36}=\dfrac{83}{36}\)