Ответы и объяснения

2014-03-26T07:56:31+00:00
1. S = 19 * 9 = 171
2. S = 50 * 61 = 3050
3. S = 12 * 35 / 2 = 210
4. S = 1/2 (32 + 22) * 12 = 1/2 * 54 *12 = 324