Question

2x-y=1 2x+y=3 система​

Answer 1

$+ \begin{cases}2x - y = 1\\2x + y = 3\end{cases} \\ \\ 2x + 2x = 1 + 3 \\ 4x = 4 \\ x = 4\div 4 \\ x = 1 \\ \\ 2 \times 1 + y = 3 \\ 2 + y = 3 \\ y= 3 - 2 \\ y = 1$

Ответ: ( 1 ; 1 )