Помогите срочно (6-4 8/15):2,2= (5,4-2 1/3):7 2/3= (7,6-4 3/4):1,9=

$1)(6-4 \frac{8}{15}):2,2=(5 \frac{15}{15} - 4\frac{8}{15})* \frac{10}{22}= 1\frac{7}{15} * \frac{10}{22}= \frac{22*10}{15*22}= \frac{2}{3}$
$2) (5,4-2 \frac{1}{3}): 7\frac{2}{3}=(5 \frac{4}{10}-2 \frac{1}{3}): \frac{23}{3}=3 \frac{12-10}{30}* \frac{3}{23}=3 \frac{2}{30}* \frac{3}{23}= \frac{46*3}{15*23}=$ $\frac{2}{5}$
3) (7,6-4,75):1,9=2,85:1,9=1,5