1. В 30080
2. Четыре
3. 1 км/ч
4. Равно 3050
5. 459 + (24х4)
6. 288 + 379 = 667
7. 609; 690; 906; 960.
(4,1 - 2 3/4) : (1 16/21 + 4 2/3) = 0,21
1) 4,1 - 2 3/4 = 41/10 - 11/4 = 82/20 - 55/20 = 27/20 =1 7/20
2) 1 16/21 + 4 2/3 = 1 16/21 + 4 14/21 = 5 30/21 = 6 9/21 = 6 3/7
3) 1 7/20 : 6 3/7 = 27/20 : 45/7 = 27/20 * 7/45 = 189/900 = 21/100 = 0,21
<em>Удачи и лёгких решений!</em>