Вычислить: 1) \(1\frac{5}{2}+2\frac{2}{3}+3\frac{3}{4}\); 2) \(1\frac{5}{2}+2\frac{2}{3}\); 3) \(\frac{7}{8}+3\frac{3}{4}\).

1. \(1\frac{5}{2}+2\frac{2}{3}+3\frac{3}{4}=\frac{7}{2}+\frac{8}{3}+\frac{15}{4}=\frac{42+32+45}{12}=\frac{119}{12}=9\frac{11}{12}.\)
2. \(1\frac{5}{2}+2\frac{2}{3}=\frac{7}{2}+\frac{8}{3}=\frac{21+16}{6}=\frac{37}{6}=6\frac{1}{6}.\)
3. \(\frac{7}{8}+3\frac{3}{4}=\frac{7}{8}+\frac{15}{4}=\frac{7}{8}+\frac{30}{8}=\frac{37}{8}=4\frac{5}{8}.\)

Ответ: 1) \(9\frac{11}{12}\); 2) \(6\frac{1}{6}\); 3) \(4\frac{5}{8}\).