`5/6xx1/7-1/7xx1/6=1/7xx(5/6-1/6)=1/7xx4/6=2/21`
`8/15:4/5xx3/2=8/15xx5/4xx3/2=[4xx2xx5xx3]/[5xx3xx4xx2]=1`
5/6 x 1/7 - 1/7 x 1/6 = \(\dfrac{1}{7}x\left(\dfrac{5}{6}-\dfrac{1}{6}\right)=\dfrac{1}{7}x\dfrac{4}{6}=\dfrac{2}{21}\)
8/15 : 4/5 x 3/2= \(\dfrac{8}{15}x\dfrac{5}{4}x\dfrac{3}{2}=\dfrac{120}{120}=1\)
\(\dfrac{5}{6}\times\dfrac{1}{7}-\dfrac{1}{7}\times\dfrac{1}{6}=\dfrac{1}{7}\times\left(\dfrac{5}{6}-\dfrac{1}{6}\right)=\dfrac{1}{7}\times\dfrac{4}{6}=\dfrac{4}{42}=\dfrac{2}{21}\)
\(\dfrac{8}{15}:\dfrac{4}{5}\times\dfrac{3}{2}=\dfrac{8}{15}\times\dfrac{5}{4}\times\dfrac{2}{3}=\dfrac{120}{120}=1\)