\[\boxed{\mathbf{Страница}\mathbf{\ 50.}\mathbf{\ }\mathbf{Еуроки\ - \ ДЗ\ без\ мороки}}\]
\[\boxed{\mathbf{39.}}\]
\[\boxed{\mathbf{40.}}\]
\[На\ 36:\]
\[12 \cdot 10 = 120\]
\[12 \cdot 13 = 156\]
\[156 - 120 = 36\]
\[На\ 460:\]
\[230 \cdot 30 = 6900\]
\[230 \cdot 32 = 7360\]
\[7360 - 6900 = 460\]
\[На\ 1280:\]
\[640 \cdot 24 = 15\ 360\]
\[640 \cdot 26 = 16\ 640\]
\[16\ 640 - 15\ 360 = 1280\]
\[На\ 910:\]
\[910 \cdot 65 = 59\ 150\]
\[910 \cdot 66 = 60\ 060\]
\[60\ 060 - 59\ 150 = 910\]