a) \( 7 : 8 = x : 96 \)
\( \frac{7}{8} = \frac{x}{96} \)
\( x = \frac{7 \cdot 96}{8} = 7 \cdot 12 = 84 \)
б) \( y : 5 = \frac{31}{4} : \frac{1}{3} \)
\( y : 5 = \frac{31}{4} \cdot 3 = \frac{93}{4} \)
\( y = \frac{93}{4} \cdot 5 = \frac{465}{4} = 116,25 \)
в) \( \frac{a}{0,6} = \frac{25}{3} \)
\( a = \frac{25}{3} \cdot 0,6 = \frac{25}{3} \cdot \frac{6}{10} = \frac{25 \cdot 2}{10} = \frac{50}{10} = 5 \)
г) \( 2 + \frac{x}{3} = \frac{4}{9} \)
\( \frac{x}{3} = \frac{4}{9} - 2 \)
\( \frac{x}{3} = \frac{4}{9} - \frac{18}{9} = -\frac{14}{9} \)
\( x = -\frac{14}{9} \cdot 3 = -\frac{14}{3} = -4 \frac{2}{3} \)
Ответ: a) x = 84; б) y = 116,25; в) a = 5; г) x = -\( \frac{14}{3} \).