Ответ:

[tex]3\frac{1}{8} /2*\frac{1}{2} =2\frac{2}{3}/x\\\\\frac{25}{8} *\frac{1}{2} *\frac{1}{2} =\frac{8}{3} *\frac{1}{x} \\\\\frac{25}{32} =\frac{8}{3x} \\\\75x=256\\\\x=\frac{256}{75}[/tex]