в) 1,2(а-7) - 1,8(3 – а) при а = 4\(\frac{1}{3}\);

в) 1,2(а-7) - 1,8(3 – а) при а = 4\(\frac{1}{3}\) = 1.2\(4\frac{1}{3} - 7\) - 1.8\(3 - 4\frac{1}{3}\) = 1.2\(\frac{13}{3} - \frac{21}{3}\) - 1.8\(\frac{9}{3} - \frac{13}{3}\) = 1.2 * \(-\frac{8}{3}\) - 1.8 * \(-\frac{4}{3}\) = -\(\frac{1.2 * 8}{3}\) + \(\frac{1.8 * 4}{3}\) = -\(\frac{9.6}{3}\) + \(\frac{7.2}{3}\) = -3.2 + 2.4 = -0.8

Ответ: -0.8