4 3/8÷5 1/4=х÷12 3 (2/5х+3)-3/5х=8

Решите задачу:

$4 \frac{3}{8} : 5 \frac{1}{4} =x:12 \\ \frac{35}{8} : \frac{21}{4} =x:12 \\ \frac{35}{8} * \frac{4}{21} =x:12 \\ \frac{5}{6} =x:12 \\ x= \frac{5}{6} *12 \\ x=10$

$3( \frac{2}{5} x+3)- \frac{3}{5} x=8 \\ \frac{6}{5} x+9- \frac{3}{5} x=8 \\ \frac{3}{5} x=8-9 \\ \frac{3}{5} x=-1 \\ x=-1* \frac{5}{3} \\ x=- \frac{5}{3} \\ x=-1 \frac{2}{3}$