Subject (2). Let $x \neq-1, y \neq-2, z \neq-3$ be rational numbers such that

$$
\frac{2015}{x+1}+\frac{2015}{y+2}+\frac{2015}{z+3}=2014
$$

Calculate $\frac{x-1}{x+1}+\frac{y}{y+2}+\frac{z+1}{z+3}$

G.M.-B. No. 10/2014
Solution. Of course $\frac{x-1}{x+1}+\frac{y}{y+2}+\frac{z+1}{z+3}=3-2\left(\frac{1}{x+1}+\frac{1}{y+2}+\frac{1}{z+3}\right)$, and the parenthesis is equal to $\frac{2014}{2015}$, so the sought value is $\frac{2017}{2015}$.

What is the importance of declaring the numbers $x, y, z$ as rational? Oh, oh, oh ... we take statements directly from the newspaper, without any quality control.