[tex]( - 0.5) \times 0.62 \times ( - 3) \times ( - 2) = 1 \times ( - 1.86) = - 1.86[/tex]

[tex] - \frac{7}{11} \times ( - \frac{2}{13} ) \times \frac{11}{21} \times ( - 26) = - \frac{7 \times 11}{11 \times 21} \times \frac{2 \times 26}{13} = - \frac{1}{3} \times 4 = - \frac{4}{3} = - 1 \frac{1}{3} [/tex]

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

[tex] \frac{2}{5} \times ( - 1.2) + \frac{2}{5} \times ( - 3.8) = \frac{2}{5} \times ( - 1.2 - 3.8) = \frac{2}{5} \times ( - 5) = - \frac{2 \times 5}{5} = - 2[/tex]

[tex]( - 1.42 - ( - 3.22)) \div ( - 0.8) + ( - 0.7) \times ( - 6) = - 1.95 \\ - 1.42 - ( - 3.22) = - 1.42 + 3.22 = 1.8 \\ 1.8 \div ( - 0.8) = - 2.25\\ ( - 0.7) \times ( - 6) = 4.2 \\ - 2.25 + 4.2 = - 1.95[/tex]