Решение:
\(\frac{1}{3}\)a(a - b) - b(1 - 3a) = \(\frac{1}{3}\)a² - \(\frac{1}{3}\)ab - b + 3ab = \(\frac{1}{3}\)a² + (3 - \(\frac{1}{3}\))ab - b = \(\frac{1}{3}\)a² + \(\frac{8}{3}\)ab - b
Ответ: \(\frac{1}{3}\)a² + \(\frac{8}{3}\)ab - b