Answer:
Write its y-intercept as zero:
[tex]y=m\,x[/tex]
Step-by-step explanation:
If the line is given in slope-intercept form:
[tex]y=m\,x+b[/tex]
make sure that you keep the value of the slope (m) as it is (because you want a line parallel to this one so it has to have the same slope "m", and change the value of "b" to zero, leaving the line with the following form:
[tex]y=m\,x+0\\y=m\,x[/tex]
This forces the line to have its y-intercept at the value zero (origin of coordinates)