3. Вычислите: 1) \(\frac79+\frac23\); 2) \(\frac5{12}-\frac59\); 3) \(2\frac34+3\frac25\); 4) \(3\frac58-2\frac16\).

1. \(\frac79+\frac23=\frac79+\frac69=\frac{13}{9}=1\frac49\).
2. \(\frac5{12}-\frac59=\frac{15}{36}-\frac{20}{36}=-\frac5{36}\).
3. \(2\frac34+3\frac25=5+\frac34+\frac25=5+\frac{15}{20}+\frac8{20}=6\frac3{20}\).
4. \(3\frac58-2\frac16=\frac{29}{8}-\frac{13}{6}=\frac{87}{24}-\frac{52}{24}=\frac{35}{24}=1\frac{11}{24}\).

Ответ: 1) \(1\frac49\); 2) \(-\frac5{36}\); 3) \(6\frac3{20}\); 4) \(1\frac{11}{24}\).