\[\boxed{\mathbf{2.431}}\]
Пояснение.
Решение.
\[\textbf{а)}\ \frac{2}{3}x = 1\]
\[x = 1\ :\frac{2}{3}\]
\[x = \frac{3}{2} = 1,5\]
\[Ответ:x = 1,5.\]
\[\textbf{б)}\ \frac{51}{62}y = 1\]
\[y = 1\ :\frac{51}{62}\]
\[y = \frac{62}{51} = 1\frac{11}{51}\]
\[Ответ:y = 1\frac{11}{51}.\]
\[\textbf{в)}\ 0,4a = 1\]
\[a = 1\ :0,4\]
\[a = \frac{10}{4} = \frac{5}{2}\]
\[a = 2,5\]
\[Ответ:a = 2,5.\]
\[\textbf{г)}\ 0,9b = 1\]
\[b = 1\ :0,9\]
\[b = \frac{10}{9} = 1\frac{1}{9}\]
\[Ответ:b = 1\frac{1}{9}.\]
\[\textbf{д)}\ \frac{7}{25}x = \frac{7}{25}\]
\[x = 1\]
\[Ответ:x = 1.\]
\[\textbf{е)}\ \frac{13}{6}y = \frac{13}{6}\]
\[y = 1\]
\[Ответ:y = 1.\]