Выполните вычисления устно:
а) 4 * 63 + 4 * 79 + 142 * 6;
б) 7 * 125 + 3 * 62 + 63 * 3;
в) 17 * 27 + 23 * 17 + 50 * 19;
г) 38 * 46 + 62 * 46 + 100 * 54.
4 * 63 + 4 * 79 + 142 * 6 = 4 * (63 + 79) + 142 * 6 = 4 * 142 + 142 * 6 = 142 * (4 + 6) = 142 * 10 = 1420
7 * 125 + 3 * 62 + 63 * 3 = 7 * 125 + 3 * (62 + 63) = 7 * 125 + 3 * 125 = 125 * (7 + 3) = 125 * 10 = 1250
17 * 27 + 23 * 17 + 50 * 19 = 17 * (27 + 23) + 50 * 19 = 17 * 50 + 50 * 19 = 50 * (17 + 19) = 50 * 36 = 50 * (30 + 6) = 1500 + 300 = 1800
38 * 46 + 62 * 46 + 100 * 54 = 46 * (38 + 63) + 100 * 54 = 46 * 100 + 100 * 54 = 100 * (46 + 54) = 100 * 100 = 10000