\[\boxed{\mathbf{Страница\ 60.}еуроки - ответы\ на\ пятёрку}\]
\[\boxed{\mathbf{9.}\mathbf{1.}}\]
\[\textbf{а)}\]
\[\textbf{б)}\ \]
\[\boxed{\mathbf{9.2.}}\]
\[\textbf{а)}\ 90 \cdot x = 180\ 720\ \]
\[x = 180\ 720\ :90\]
\[x = 18\ 072\ :9\]
\[x = 2008.\]
\[\textbf{б)}\ 115\ 620\ :y = 564\]
\[y = 115\ 620\ :564\]
\[y = 205.\]
\[\boxed{\mathbf{9.3.}}\]
\[\textbf{а)}\ a\ :(b - c)\]
\[\textbf{б)}\ (x + y)\ :(x - y)\]
\[\boxed{\mathbf{9.4.}}\]
\[a \cdot 9 > a \cdot 4\]
\[b \cdot 5 = 5 \cdot b\]
\[c\ :8 < c\ :2\]
\[36\ :d > 24\ :d\]
\[(x \cdot 7) \cdot y > y \cdot (3 \cdot x)\]
\[m \cdot 2 + m \cdot 4 = 6 \cdot m\]
\[\boxed{\mathbf{9.5.}}\]
\[56\ 000\ :80 < 58\ 752\ :72 < 60\ 000\ :60\]
\[700 < 58\ 752\ :72 < 1000\]
\[\boxed{\mathbf{9.6.}}\]
\[60 < xx < 70\]
\[61\ год - дедушке;\]
\[16\ лет - Степе.\]
\[61 - 16 = 45\ (лет) - моложе.\]
\[Ответ:на\ 45\ лет.\]