\[1)\ 10\ :\frac{1}{8} = x\ :1\frac{1}{4}\]
\[10 \bullet 8 = x\ :\frac{4 + 1}{4}\]
\[80 = x \bullet \frac{4}{5}\]
\[x = 80 \bullet \frac{5}{4} = 20 \bullet 5\]
\[x = 100.\]
\[Ответ:\ \ 100.\]
\[2)\ x\ :0,75 = 9\frac{1}{2}\ :14\frac{1}{4}\]
\[x\ :\frac{75}{100} = \frac{9 \bullet 2 + 1}{2}\ :\frac{14 \bullet 4 + 1}{4}\]
\[x \bullet \frac{100}{75} = \frac{19}{2} \bullet \frac{4}{57}\]
\[\frac{100}{75}x = \frac{2}{3}\]
\[x = \frac{2}{3} \bullet \frac{75}{100} = \frac{25}{50}\]
\[x = 0,5.\]
\[Ответ:\ \ 0,5.\]
\[3)\ \frac{x}{15} = \frac{1,456}{1,05}\]
\[\frac{x}{15} = \frac{1456}{1050}\]
\[x = \frac{1456}{1050} \bullet 15 = \frac{1456}{70}\]
\[x = 20,8.\]
\[Ответ:\ \ 20,8.\]