14. If it is said to you: divide 100 square cubits into 2 unknown parts and take $\frac{3}{4}$ of the side of one as the side of the other, give me each of the unknown parts (i.e., divide an area of 100 sq. cubits into 2 squares, the sides of which are in the ratio $\left.1: \frac{3}{4}\right)$.

## Problems from the Rhind Papyrus.
14. The problem reduces to the system of equations:

$$
x: y=1: \frac{3}{4} ; x^{2}+y^{2}=100
$$

It is not hard to see that $x=8 ; y=6$.

$$
\text { 15. } \begin{gathered}
\frac{2}{2 n+1}=\frac{2(n+1)}{2 n+1}:(n+1)=\left(1+\frac{1}{2 n+1}\right):(n+1)= \\
=\frac{1}{n+1}+\frac{1}{(n+1)(2 n+1)} \text {. }
\end{gathered}
$$

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