5. Решите примеры: 400 + 80 - 1 750 - 50 + 1 978 - 8 - 1 500 + 99 + 1 300 + 74 374 - 300

* 400 + 80 - 1 = 480 - 1 = 479 * 750 - 50 + 1 = 700 + 1 = 701 * 978 - 8 - 1 = 970 - 1 = 969 * 500 + 99 + 1 = 599 + 1 = 600 * 300 + 74 = 374 * 374 - 300 = 74