\(a,\dfrac{1}{2}-\left[\dfrac{3}{4}+\left(-\dfrac{5}{6}\right)\right]-\dfrac{7}{12}\)
\(=\dfrac{1}{2}-\left(-\dfrac{1}{12}\right)-\dfrac{7}{12}=\dfrac{7}{12}-\dfrac{7}{12}=0\)
\(b,\left(-3\right)-\dfrac{2}{3}+\left(-\dfrac{10}{9}-\dfrac{25}{9}\right)-\dfrac{5}{6}\)
\(=\left(-3\right)-\dfrac{2}{3}+\left(-\dfrac{35}{9}\right)-\dfrac{5}{6}\)
\(=-\dfrac{11}{3}+\left(-\dfrac{35}{9}\right)-\dfrac{5}{6}=-\dfrac{68}{9}-\dfrac{5}{6}=-\dfrac{151}{18}\)
\(c,\left(\dfrac{5}{-7}-\dfrac{-5}{-7}\right)+\dfrac{4}{3}\)
\(=-\dfrac{10}{7}+\dfrac{4}{3}=-\dfrac{2}{21}\)
\(\dfrac{7}{3}+\left[\left(-\dfrac{5}{6}\right)+\left(-\dfrac{2}{3}\right)\right]\)
\(=\dfrac{7}{3}+\left(-\dfrac{3}{2}\right)=\dfrac{5}{6}\)
\(\dfrac{4}{3}-\left[\left(-\dfrac{11}{6}\right)-\left(\dfrac{2}{9}+\dfrac{5}{3}\right)\right]\)
\(=\dfrac{4}{3}-\left[\left(-\dfrac{11}{6}\right)-\dfrac{17}{9}\right]=\dfrac{4}{3}-\left(-\dfrac{67}{18}\right)=\dfrac{91}{18}\)
\(\dfrac{2}{3}-\left[\left(-\dfrac{7}{4}\right)-\left(\dfrac{1}{2}+\dfrac{3}{8}\right)\right]\)
\(=\dfrac{2}{3}-\left[\left(-\dfrac{7}{4}\right)-\dfrac{7}{8}\right]=\dfrac{2}{3}-\left(-\dfrac{21}{8}\right)=\dfrac{79}{24}\)
\(\dfrac{1}{3}-\left[\left(-\dfrac{5}{4}\right)-\left(\dfrac{1}{4}+\dfrac{3}{8}\right)\right]\)
\(=\dfrac{1}{3}-\left[\left(-\dfrac{5}{4}\right)-\dfrac{5}{8}\right]=\dfrac{1}{3}-\left(-\dfrac{15}{8}\right)=\dfrac{53}{24}\)
Có gì sai cho thông cảm ạ! Vì bạn cho hơi nhiều phép tính
