3а+8а=1,87
7z-3z=5,12
2t+5t+3,18=25,3

3a + 8a = 1,8711a = 1,87 : 11a = 0,17Проверка: 3 * 0,17 + 8 * 0,17 = 0,51 + 1,36 = 1,877z - 3z = 5,124z = 5,12z = 5,12 : 4z = 1,28Проверка: 7 * 1,28 - 3 * 1,28 = 8,96 - 3,84 = 5,122t + 5t + 3,18 = 25,37t = 25,3 - 3,187t = 22,12t = 22,12 : 7t = 3,16Проверка: 2 * 3,16 + 5 * 3,16 + 3,18 = 6,32 + 15,8 + 3,18 = 25,3