\[\boxed{\mathbf{3.43}}\]
Пояснение.
Решение.
\[Для\ решения\ уравнений\ \]
\[воспользуемся\ основным\ \]
\[свойством\ пропорции.\]
\[\textbf{а)}\ \frac{42,6}{x} = \frac{5,34}{4,45}\]
\[x = \frac{42,6 \cdot 4,45}{5,34} = \frac{426 \cdot 445}{10 \cdot 534} =\]
\[= \frac{71 \cdot 89}{2 \cdot 89} = \frac{71}{2}\]
\[x = 35,5.\]
\[\textbf{б)}\ \frac{32,4}{8} = \frac{y}{0,6}\]
\[y = \frac{32,4 \cdot 0,6}{8} = 8,1 \cdot 0,3\]
\[y = 2,43.\]
\[\textbf{в)}\ \frac{1,7}{2,1} = \frac{5,1}{p}\]
\[p = \frac{5,1 \cdot 2,1}{1,7} = 3 \cdot 2,1\]
\[p = 6,3.\]
\[\textbf{г)}\ \frac{q}{0,08} = \frac{9,8}{0,28}\]
\[q = \frac{9,8 \cdot 0,08}{0,28} = \frac{9,8 \cdot 8}{28} = 1,4 \cdot 2\]
\[q = 2,8.\]