Ответ:
\(\frac{4}{5}+\frac{4}{7}=\frac{48}{35}\).
\(3\frac{3}{8}+2\frac{11}{4}=\frac{27}{8}+\frac{19}{4}=\frac{65}{8}\).
\(\frac{48}{35}\cdot\frac{65}{8}=\frac{78}{7}=11\frac{1}{7}\).
Ответ: \(11\frac{1}{7}\)
\(\frac{4}{5}+\frac{4}{7}=\frac{48}{35}\).
\(3\frac{3}{8}+2\frac{11}{4}=\frac{27}{8}+\frac{19}{4}=\frac{65}{8}\).
\(\frac{48}{35}\cdot\frac{65}{8}=\frac{78}{7}=11\frac{1}{7}\).
Ответ: \(11\frac{1}{7}\)