1. Вычислите: 1) 7,8 · 4/13 − 61,5 : 13 2/3 + 198,8; 2) 19,25 · 5/11 + 5,76 · 5/12 − 13,009; 3) 4,625 · 2 2/15 : 2,96 − 2 4/7; 4) 30,25 : 4 5/7 : 1,05 − 2 1/6.

1. \(7.8\cdot\frac4{13}-61.5:\left(13\frac23\right)+198.8=2.4-4.5+198.8=196.7\).
2. \(19.25\cdot\frac5{11}+5.76\cdot\frac5{12}-13.009=8.75+2.4-13.009=-1.859\).
3. \(4.625\cdot2\frac2{15}:2.96-2\frac47=\frac{37}{8}\cdot\frac{32}{15}:\frac{74}{25}-\frac{18}{7}=\frac{148}{15}\cdot\frac{25}{74}-\frac{18}{7}=\frac{10}{3}-\frac{18}{7}=\frac{16}{21}\).
4. \(30.25:4\frac57:1.05-2\frac16=\frac{121}{4}:\frac{33}{7}:\frac{21}{20}-\frac{13}{6}=\frac{385}{12}\cdot\frac{20}{21}-\frac{13}{6}=\frac{275}{9}-\frac{13}{6}=\frac{511}{18}\).

Ответ: 1) 196,7; 2) −1,859; 3) \(16/21\); 4) \(511/18\).