Question

(x – 3y = -1
(2x + y = 5​

Answer 1

Если это система то,
(x=3y-1
(2x-y=5
6y-2+y=5
7y=7
y=1

x=3-1
x=2

Answer 2

$x - 3y = - 1 \\ x - 3y + 1 = - 1 + 1 \\ x - 3y + 1 = 0$

$2x + y = 5 \\ 2x + y - 5 = 5 - 5 \\ 2x + y - 5 = 0$