30*20-7*8 3000-7*40 40*50-138 70*30-9*50 (235+65)*3-645 (2600+1400):200-1350

Решение примеров:Пример №1.30 * 20 - 7 * 8 = 544;30 * 20 = 600;7 * 8 = 56;600 - 56 = 544.Пример №2.3000 - 7 * 40 = 2720;7 * 40 = 280;3000 - 280 = 2720.Пример №3.40 * 50 - 138 = 1862;40 * 50 = 2000;2000 - 138 = 1862.Пример №4.70 * 30 - 9 * 50 = 1650;70 * 30 = 2100;9 * 50 = 450;2100 - 450 = 1650.Пример №5.(235 + 65) * 3 - 645 = 255;235 + 65 = 300;300 * 3 = 900;900 - 645 = 255.Пример №6.(2600 + 1400) : 200 - 1350 = -1330;2600 + 1400 = 4000;4000 / 200 = 20;20 - 1350 = -1330.