a)
[tex]4 - 8 \frac{1}{2} + ( - 21 \frac{1}{3} ) = - 4\frac{1}{2} - 21 \frac{1}{3} = - 4 \frac{3}{6} - 21 \frac{2}{6} = - 25 \frac{5}{6} [/tex]
b)
[tex] - 3 \frac{1}{6} - ( - 1 \frac{ 3}{4}) = - 3 \frac{1}{6} + 1 \frac{3}{4} = - 3 \frac{2}{12} + 1 \frac{9}{12} = 1 \frac{9}{12} - 3 \frac{2}{12} = - 2 \frac{7}{12} [/tex]
c)
[tex] - 2 \frac{3}{4} + 1 \frac{3}{5} - ( - 0.3) = - 2 \frac{15}{20} + 1 \frac{12}{20} + \frac{3}{10} = 1 \frac{12}{20} - 2 \frac{15}{20} + \frac{6}{20} = \frac{32}{20} - \frac{55}{20} + \frac{6}{20} = - \frac{17}{20} [/tex]
d)
[tex]2 \frac{3}{4} \times ( - 1 \frac{3}{5} ) = \frac{11}{4} \times ( - \frac{8}{5} ) = - \frac{22}{5} = - 4 \frac{2}{5} [/tex]
e)
[tex]2.8 \div ( - 0.07) = 28 \div ( - 0.7) = 28 \times ( - \frac{10}{7} ) = 4 \times ( - 10) = - 40[/tex]
