\(\dfrac{6}{25}+\dfrac{3}{5}=\dfrac{6}{25}+\dfrac{15}{25}=\dfrac{21}{25}\)
\(\dfrac{8}{3}-\dfrac{3}{9}=\dfrac{24}{9}-\dfrac{3}{9}=\dfrac{21}{9}=\dfrac{7}{3}\)
\(\dfrac{1}{2}:4=\dfrac{1}{2}\times\dfrac{1}{4}=\dfrac{1}{8}\)
\(\dfrac{3}{2}\times\left(\dfrac{4}{8}+\dfrac{5}{2}\right)=\dfrac{3}{2}\times3=\dfrac{9}{2}\)
\(\dfrac{6}{25}+\dfrac{3}{5}=\dfrac{21}{25}\)
\(\dfrac{8}{3}-\dfrac{3}{9}=\dfrac{7}{3}\)
\(\dfrac{1}{2}\div4=\dfrac{1}{8}\)
\(\dfrac{3}{2}\times\left\{\dfrac{4}{8}+\dfrac{5}{2}\right\}\)
\(=\dfrac{2}{3}\times3\)
\(=2\)