a) $$1\frac{5}{17}\cdot(7-2\frac{4}{11})$$
- $$7-2\frac{4}{11} = 7-\frac{26}{11} = \frac{77-26}{11} = \frac{51}{11}$$
- $$1\frac{5}{17} \cdot \frac{51}{11} = \frac{22}{17} \cdot \frac{51}{11} = \frac{2 \cdot 1}{1 \cdot 1} \cdot \frac{3 \cdot 17}{1} = 6$$
б) (4,2:1,2 - 1,05)⋅1,6
- $$4,2 : 1,2 = 42 : 12 = \frac{42}{12} = \frac{7}{2} = 3,5$$
- $$3,5 - 1,05 = 2,45$$
- $$2,45 \cdot 1,6 = 3,92$$
Ответ: а) 6; б) 3,92