The red line (line m) slants downhill to the right, so its
slope is negative.  It has a negative y-intercept because
it crosses the y-axis below the origin.  The green
line (line n) is parallel to line m and has a positive 
y-intercept because it crosses the y-axis above the origin.
Line n crosses the x-axis to the right of the origin at the 
point circled and marked with a question mark.
Since it is to the right of the origin, 

the x-intercept of n must be POSITIVE.

Edwin