\(A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}=\dfrac{21}{36}+\dfrac{5}{12}.\dfrac{1}{6}-\dfrac{11}{36}=\dfrac{5}{18}+\dfrac{5}{12}.\dfrac{1}{6}=\dfrac{20}{72}+\dfrac{5}{72}=\dfrac{25}{72}\)
\(B=1\dfrac{3}{8}+\dfrac{1}{8}:\left(0,75-\dfrac{1}{2}\right)-25\%.\dfrac{1}{2}=\dfrac{11}{8}+\dfrac{1}{8}:\dfrac{1}{4}-\dfrac{1}{8}=\dfrac{5}{4}+\dfrac{1}{2}=\dfrac{7}{4}\)
a) Ta có: \(A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}\)
\(=\dfrac{7}{12}+\dfrac{5}{72}-\dfrac{11}{36}\)
\(=\dfrac{42+5-22}{72}\)
\(=\dfrac{25}{72}\)
b) Ta có: \(A=1\dfrac{3}{8}+\dfrac{1}{8}:\left(0.75-\dfrac{1}{2}\right)-25\%\cdot\dfrac{1}{2}\)
\(=\dfrac{11}{8}+\dfrac{1}{8}:\dfrac{1}{4}-\dfrac{1}{4}\cdot\dfrac{1}{2}\)
\(=\dfrac{11}{8}-\dfrac{1}{8}+\dfrac{1}{2}\)
\(=\dfrac{10}{8}+\dfrac{1}{2}\)
\(=\dfrac{5}{4}+\dfrac{2}{4}=\dfrac{7}{4}\)