Chuyển hỗn số sau thành phân số 7 2 5 = … …

$9\frac{4}{9}=9+\frac{4}{9}=\frac{9\times 9+4}{9}=\frac{{\displaystyle 85}}{{\displaystyle 9}}$

$7\frac{1}{8}+6\frac{3}{4}=\frac{57}{8}+\frac{27}{4}=\frac{57}{8}+\frac{54}{8}=\frac{57+54}{8}=\frac{{\displaystyle 111}}{{\displaystyle 8}}$

$3\frac{1}{2}+4\frac{3}{8}=\frac{7}{2}+\frac{35}{8}=\frac{28}{8}+\frac{35}{8}=\frac{28+35}{8}=\frac{63}{8}$

$4\frac{2}{5}-3\frac{1}{5}=\frac{22}{5}-\frac{16}{5}=\frac{22-16}{5}=\frac{6}{5}$

$1\frac{1}{6}-1\frac{1}{7}=\frac{7}{6}-\frac{8}{7}=\frac{49}{42}-\frac{48}{42}=\frac{49-48}{42}=\frac{1}{42}$