Question 963969
A parallel line would have the same slope, different y intercept.
{{{y=25x+b}}}, {{{b<>45}}}
.
.
.
Lines that never cross are parallel. 
So a line parallel to {{{y=25x+45}}} would be 
{{{y=25x+b}}}, {{{b<>45}}}
and a line parallel to {{{y=20x+120}}} would be
{{{y=20x+b}}},{{{b<>120}}}