What is the equation of the line that has an x intercept of -5

The equation would be 5*x=

There are an infinite number of lines that have an x-intercept of (-5,0).  One of them is the x-axis, for which the slope is zero; another is the line x = -5, for which the slope is undefined.  Lots and lots more!

If we arbitrarily choose m = 2, and start with (-5,0), we go 1 unit to the right and from there 2 units up.  Plot this new point, (-3,2).  Draw a line thru (-3,2) and (-5,0).  Please note that this is only one example of many possible examples.