(x-0.8):16/19=3 1/6:13 1/3

Решаем пропорцию:

$\frac{x-0,8}{ \frac{16}{19} } = \frac{3 \frac{1}{6} }{13 \frac{1}{3} } \\ \\ \frac{16}{19}* 3\frac{1}{6} =(x-0.8)*13 \frac{1}{3}$

$\frac{16}{19} * \frac{19}{6} =13 \frac{1}{3} x- \frac{8}{10} * \frac{40}{3} \\ \\ 13 \frac{1}{3} x= \frac{16}{6} + \frac{32}{3} \\ \\ 13 \frac{1}{3} x= \frac{16}{6} + \frac{64}{6} \\ \\ 13 \frac{1}{3} x= \frac{80}{6} \\ \\ x=\frac{80}{6}:13 \frac{1}{3} \\ \\ x=\frac{80}{6}* \frac{3}{40} \\ \\ x=\frac{2}{2}* \frac{1}{1} \\ \\ x=1$