Question

x+y+ y
8
x
10
52
= 4,
x-y
5
=
1;

Answer 1

$\begin{cases}\frac{x+y}{8}+\frac{y}{2}=4\\ \frac{x}{10}-\frac{x-y}{5}=1\end{cases}\Leftrightarrow \begin{cases}x+y+4y=32\\x-2(x-y)=10\end{cases}\Leftrightarrow \begin{cases}x+5y=32\\x-2x+2y=10\end{cases}\Leftrightarrow \begin{cases}x+5y=32\\-x+2y=10\end{cases}$

$7y=42\Rightarrow y=6\Rightarrow x+5\cdot 6=32\Rightarrow x=32-30=2$

Ответ: $(x,y)=(2,6)$