Question 1124695
parallel lines have the same slope, and the segment has a slop of 5/2
the other line has a change of y of -6.5 (from right to left).  The change in x has to be -2.6.  That would make x be -0.5.

equations of both lines 
y-3=2.5(x-1) or y=2.5x+0.5

y-3.3=2.5(x-2.1) or y=2.5x-1.95

{{{graph(300,300,-10,10,-10,10,2.5x+0.5,2.5x-1.95)}}}