1. Выполни вычисления: 70 + 40 = 810 - 300 = 370 + 60 = 250 + 430 = 300 - 90 = 840 + 60 = 320 - 80 = 590 - 270 =

Решение:

1. \[70 + 40 = 110\]
2. \[810 - 300 = 510\]
3. \[370 + 60 = 430\]
4. \[250 + 430 = 680\]
5. \[300 - 90 = 210\]
6. \[840 + 60 = 900\]
7. \[320 - 80 = 240\]
8. \[590 - 270 = 320\]

Ответ: 110, 510, 430, 680, 210, 900, 240, 320