Question

Решения способом сложения
{x-y-7=0
{3x-y+1=0

{x+3y-1=0
{-x+4y+8=0

{x-2y+3=0
{-x+3y-2=0

{x-y+2=0
{3x+y-4=0

{2x+y-3=0
{-x-y+4=0