4) 3 2/3-7 =

4) $$3\frac{2}{3} - 7 = \frac{3 \cdot 3 + 2}{3} - 7 = \frac{11}{3} - \frac{7}{1} = \frac{11}{3} - \frac{7 \cdot 3}{1 \cdot 3} = \frac{11}{3} - \frac{21}{3} = \frac{11 - 21}{3} = \frac{-10}{3} = -3\frac{1}{3}$$

Ответ: $$-3\frac{1}{3}$$