Slope: (3-(-1))/(-6-2)=4/(-8)=-½.
To find the line, use slope-intercept form of a line:
y-(-1)=-½(x-2), y+1=-½x+1, y=-x/2.
(Or we could simply realise that the magnitude of the y-coord is half the value of the x-coord, but then y is negated.)
What we have is a line passing through the origin (0,0) leaning backwards at a shallow angle to the horizontal.