7/12 - 1/6 = 7/12 - 2/12 = 5/12
10/7 - 2/3 = 16/21
a) = 7/12 - 1/6 = 5/12
b) = 10/7 - 2/3 = 16/21
\(a,\dfrac{7}{12}-\dfrac{3}{4}\times\dfrac{2}{9}=\dfrac{7}{12}-\dfrac{1}{6}=\dfrac{7}{12}-\dfrac{2}{12}=\dfrac{5}{12}\)
\(b,\dfrac{10}{7}-\dfrac{4}{15}:\dfrac{2}{5}=\dfrac{10}{7}-\dfrac{4}{15}\times\dfrac{5}{2}=\dfrac{10}{7}-\dfrac{2}{3}=\dfrac{30}{21}-\dfrac{14}{21}=\dfrac{16}{21}\)
a. 7/12 - 3/4* 2/9 = 7/12 - 1/6 = 5/12
b. 10/7-4/15: 2/5 = 10/7 - 2/3 = 16/21