a) \(\dfrac{1}{2}-\dfrac{1}{6}=\dfrac{3}{6}-\dfrac{1}{6}=\dfrac{3-1}{6}=\dfrac{2}{6}=\dfrac{1}{3}\)

b) \(\dfrac{3}{4}-\dfrac{5}{8}=\dfrac{12}{8}-\dfrac{5}{8}=\dfrac{12-5}{8}=\dfrac{7}{8}\)

c) \(\dfrac{7}{10}-\dfrac{2}{5}=\dfrac{7}{10}-\dfrac{4}{10}=\dfrac{7-4}{10}=\dfrac{3}{10}\)

d) \(\dfrac{7}{12}-\dfrac{1}{3}=\dfrac{7}{12}-\dfrac{4}{12}=\dfrac{7-4}{12}=\dfrac{3}{12}=\dfrac{1}{4}\)

a) \(\dfrac{1}{3}\)
b)\(\dfrac{1}{8}\)
c)\(\dfrac{3}{10}\)
d)\(\dfrac{3}{12}\)

a) \(\dfrac{2}{3}+\dfrac{4}{9}=\dfrac{6}{9}+\dfrac{4}{9}+\dfrac{6+3}{9}=\dfrac{10}{9}\)

b)\(\dfrac{1}{10}+\dfrac{2}{5}=\dfrac{1}{10}+\dfrac{4}{10}=\dfrac{1+4}{10}=\dfrac{5}{10}=\dfrac{1}{2}\)

c) \(\dfrac{7}{22}-\dfrac{3}{11}=\dfrac{7}{22}-\dfrac{6}{22}=\dfrac{7-6}{22}=\dfrac{1}{22}\)

d) \(\dfrac{5}{6}-\dfrac{5}{12}=\dfrac{10}{12}-\dfrac{5}{12}=\dfrac{10-5}{12}=\dfrac{5}{12}\)

a) \(\dfrac{3}{5}:\dfrac{3}{4}=\dfrac{3}{5}\cdot\dfrac{4}{3}=\dfrac{4}{5}\)

b) \(\dfrac{2}{5}:\dfrac{3}{10}=\dfrac{2}{5}\cdot\dfrac{10}{3}=\dfrac{4}{3}\)

c) \(\dfrac{1}{8}:\dfrac{1}{6}=\dfrac{1}{8}\cdot6=\dfrac{6}{8}=\dfrac{3}{4}\)

a: \(=\dfrac{3}{5}\cdot\dfrac{4}{3}=\dfrac{12}{15}=\dfrac{4}{5}\)

b: \(=\dfrac{2}{5}\cdot\dfrac{10}{3}=\dfrac{20}{15}=\dfrac{4}{3}\)

c: \(=\dfrac{1}{8}\cdot6=\dfrac{6}{8}=\dfrac{3}{4}\)

a, \(\dfrac{3}{5}:\dfrac{3}{4}=\dfrac{3}{5}x\dfrac{4}{3}=\dfrac{12}{15}\)

b, \(\dfrac{2}{5}:\dfrac{3}{10}=\dfrac{2}{5}x\dfrac{10}{3}=\dfrac{4}{3}\)

c, \(\dfrac{1}{8}:\dfrac{1}{6}=\dfrac{1}{8}x\dfrac{6}{1}=\dfrac{3}{4}\)

Helpp em với ạ^^

b: \(=\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9-10}{15}-\dfrac{7}{2}\)

\(=\dfrac{4-35}{10}+\dfrac{3}{5}\cdot\dfrac{15}{-1}\)

\(=\dfrac{-31}{10}-9=\dfrac{-31}{10}-\dfrac{90}{10}=-\dfrac{121}{10}\)

c: \(=\dfrac{48-5}{12}\cdot\dfrac{1}{3}+\dfrac{7}{36}=\dfrac{43}{36}+\dfrac{7}{36}=\dfrac{50}{36}=\dfrac{25}{18}\)

d: \(=\dfrac{17}{6}:\dfrac{6}{5}+\dfrac{-7}{12}\)

\(=\dfrac{85}{36}-\dfrac{7}{12}=\dfrac{85}{36}-\dfrac{21}{36}=\dfrac{64}{36}=\dfrac{16}{9}\)

a) \(\left(\dfrac{1}{4}+\dfrac{1}{12}\right):\dfrac{1}{13}\)

\(=\left(\dfrac{3}{12}+\dfrac{1}{12}\right):\dfrac{1}{13}\)

\(=\dfrac{4}{12}\times13\)

\(=\dfrac{1}{3}\times13\)

\(=\dfrac{13}{3}\)

b) \(\dfrac{3}{5}:\dfrac{2}{9}-\dfrac{1}{10}\)

\(=\dfrac{3}{5}\times\dfrac{9}{2}-\dfrac{1}{10}\)

\(=\dfrac{27}{10}-\dfrac{1}{10}\)

\(=\dfrac{26}{10}\)

\(=\dfrac{13}{5}\)

a) \(=\dfrac{157}{8}.\dfrac{12}{7}-\dfrac{61}{4}.\dfrac{12}{7}=\dfrac{12}{7}\left(\dfrac{157}{8}-\dfrac{61}{4}\right)=\dfrac{12}{7}.\dfrac{35}{8}=\dfrac{15}{2}\)

b) \(\dfrac{2}{5}.\dfrac{1}{3}-\dfrac{2}{15}\div\dfrac{1}{5}+\dfrac{3}{5}.\dfrac{1}{3}=\dfrac{1}{3}\left(\dfrac{2}{5}+\dfrac{3}{5}\right)-\dfrac{2}{15}.5=\dfrac{1}{3}.1-\dfrac{2}{3}=\dfrac{1}{3}-\dfrac{2}{3}=-\dfrac{1}{3}\)

c) \(=-\dfrac{80}{9}\)

d) \(=-\dfrac{1}{6}\)

a.=\(\dfrac{157}{8}:\dfrac{7}{12}-\dfrac{61}{4}:\dfrac{7}{12}=\dfrac{471}{14}-\dfrac{183}{7}=\dfrac{15}{2}\)

b.=\(\dfrac{2}{15}-\dfrac{2}{3}+\dfrac{1}{5}=-\dfrac{1}{3}\)

c.\(\left(\dfrac{10}{3}+2.5\right):\left(\dfrac{19}{6}-\dfrac{21}{5}\right)-\dfrac{11}{31}=\dfrac{35}{6}:\left(-\dfrac{31}{30}\right)-\dfrac{11}{31}=-\dfrac{175}{31}-\dfrac{11}{31}=-6\)

d.\(\left[6+\dfrac{1}{8}-\dfrac{1}{2}\right]:\dfrac{3}{12}=\dfrac{45}{8}:\dfrac{3}{12}=\dfrac{45}{2}\)

a) Đ

b) S 

\(\dfrac{7}{10}-\dfrac{1}{5} \\ =\dfrac{7}{10}-\dfrac{2}{10}\\ =\dfrac{5}{10}=\dfrac{1}{2}\)

c) S

\(\dfrac{5}{4}+\dfrac{5}{12}\\ =\dfrac{15}{12}+\dfrac{5}{12}\\ =\dfrac{20}{12}=\dfrac{5}{3}\)

d) Đ

\(a,\dfrac{13}{14}\cdot\dfrac{-7}{8}+\dfrac{-3}{2}\)

\(=-\dfrac{13}{16}+\dfrac{-3}{2}\)

\(=-\dfrac{13}{16}+\dfrac{-24}{16}\)

\(=-\dfrac{37}{16}\)

\(b,\dfrac{5}{17}+\dfrac{-15}{34}\cdot\dfrac{2}{5}\)

\(=\dfrac{5}{17}+\dfrac{-3}{17}\)

\(=\dfrac{2}{17}\)

\(c,\dfrac{1}{5}:\dfrac{1}{10}-\dfrac{1}{3}\cdot\left(\dfrac{6}{5}-\dfrac{2}{4}\right)\)

\(=2-\dfrac{1}{3}\cdot\dfrac{7}{10}\)

\(=2-\dfrac{7}{30}\)

\(=\dfrac{53}{30}\)

\(d,\dfrac{-3}{4}:\left(\dfrac{12}{-5}-\dfrac{-7}{10}\right)\)

\(=\dfrac{-3}{4}:\dfrac{-17}{10}\)

\(=\dfrac{15}{34}\)

a)

\(\dfrac{5}{6}\times\dfrac{1}{3}\\ =\dfrac{5\times1}{6\times3}=\dfrac{5}{18}\)

b)

\(\dfrac{5}{6}:\dfrac{1}{3}=\dfrac{5}{6}\times\dfrac{3}{1}\\ =\dfrac{15}{6}\\ =\dfrac{5}{2}\)

c)

\(\dfrac{5}{3}-\dfrac{1}{3}:\dfrac{1}{4}\\ =\dfrac{5}{3}-\dfrac{1}{3}\times4\\ =\dfrac{5}{3}-\dfrac{4}{3}\\ =\dfrac{1}{3}\)

\(a,\dfrac{5}{6}x\dfrac{1}{3}=\dfrac{5}{18}\\ b,\dfrac{5}{6}:\dfrac{1}{3}=\dfrac{5}{2}\\ c,\dfrac{5}{3}-\dfrac{1}{3}:\dfrac{1}{4}=\dfrac{5}{3}-\dfrac{4}{3}=\dfrac{1}{3}\)