Task 6. In an acute-angled triangle $\mathrm{ABC}$, angle $\mathrm{B}$ is $30^{\circ}, \mathrm{BC}=12$. The altitude CD of triangle $\mathrm{ABC}$ and the altitude DE of triangle BDC are drawn. Find BE.
Answer: 9

Task 7.3a 2016 The number of books in the school library fund increased by $0.4 \%$, and in 2017 - by $0.8 \%$, remaining less than 50 thousand. By how many books did the library fund increase in 2017?

Answer: 251

Task 8. A rectangle is divided into six squares (see figure). What is the side of the larger square if the side of the smaller one is 2?

![](https://cdn.mathpix.com/cropped/2024_05_06_c3f957dc43000ad5fba0g-1.jpg?height=382&width=457&top_left_y=1828&top_left_x=888)

Answer: 14