\[\boxed{\text{5.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[x \cdot 9 = 270\]
\[x = 270\ :9\]
\[x = 30.\]
\[x\ :8 = 70\]
\[x = 70 \cdot 8\]
\[x = 560.\]
\[52\ :x = 13\]
\[x = 52\ :13\]
\[x = 4.\ \]