\[\boxed{\text{1135\ (1135).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[2k = 3 \Longrightarrow \text{\ \ }k = 1,5\]
\[y = \text{kx},\ \ \]
\[y = 1,5x\]
\[1,5 \cdot 5 = a\ \]
\[a = 7,5\]
\[Ответ:a = 7,5.\ \]