ж) $$m + \frac{3}{8}m = \frac{1}{4}$$
$$ \frac{8}{8}m + \frac{3}{8}m = \frac{1}{4} $$
$$ \frac{11}{8}m = \frac{1}{4} $$
$$ m = \frac{1}{4} : \frac{11}{8} $$
$$ m = \frac{1}{4} \cdot \frac{8}{11} $$
$$ m = \frac{1 \cdot 8}{4 \cdot 11} $$
$$ m = \frac{1 \cdot 2}{1 \cdot 11} $$
$$ m = \frac{2}{11} $$
Ответ: $$\frac{2}{11}$$