-8+4 3/7+ 2 11/21=??? 2.2+(-4 1/3)+(-1 13/15)=???

Решите задачу:

$- 8 + 4 \frac{3}{7} + 2 \frac{11}{21} = - 8 + 4 \frac{9}{21} +2 \frac{11}{21} =$
$- 7 \frac{21}{21} + 6 \frac{20}{21} = - 1 \frac{1}{21}$

$2.2 + ( - 4 \frac{1}{3} ) + ( - 1 \frac{13}{15} ) =$ $2 \frac{1}{5} -4 \frac{5}{15} - 1 \frac{13}{15} = 2 \frac{3}{15} - 5 \frac{18}{15} = \frac{33}{15} - \frac{93}{15} =$ $- \frac{60}{15} = - 4$