Find the equation of the line that passes through (-2,5) and (-6,-3).
There are a number of ways to do this.
y=mx+b Put in the points x,y for each point, you will have two equations with two unknowns (m,b). Solve for m,b.
5=-2m+b
-3=-6m+b
subtract the upper equation from the lower...
-8=-4m and you have m. Put that back into one equation, and you have b.