\(\frac{39}{40}\): \(\frac{6}{7}\)\(\times\)\(\frac{3}{8}\)
=\(\frac{39}{40}\)\(\times\)\(\frac{7}{6}\)\(\times\)\(\frac{3}{8}\)
= \(\frac{91}{80}\)\(\times\frac{3}{8}\)=\(\frac{273}{640}\)
\(\frac{39}{40}:\frac{6}{7}X\frac{3}{8}=\frac{39}{40}X\frac{7}{6}X\frac{3}{8}=\frac{39X7X3}{40X6X8}=\frac{273}{640}\)
Chúc bạn học tốt!!!!!!!!!