Х-у=1 ху=6
{х-у=1, ху=6}
{x=y+1, (y+1)y=6}
{x=y+1, y^2+y-6=0}
{x=y+1, (y+3)(y-2)=0}
{x=y+1, y1=-3; y2=2}
{x1=-3+1=-2; x2=2+1=3, y1=-3; y2=2}