1) Б

[tex] \frac{1}{3} + \frac{1}{6} = \frac{2}{6} + \frac{1}{6} = \frac{3}{6} = \frac{1}{2} [/tex]

2) В

[tex] - 1 \frac{3}{5} \times 1 \frac{1}{4} = - \frac{8 \times 5}{5 \times 4} = - [/tex]

3) Д

[tex] \frac{1}{3} - 1 \frac{2}{3} = - 1 \frac{1}{3} = - \frac{4}{3} [/tex]

4) А

[tex] - 1 \frac{1}{3} \div ( - \frac{2}{3} ) = - \frac{4}{3} \times ( - \frac{ 3}{2} ) = \frac{4 \times 3}{3 \times 2} = 2[/tex]