Select a couple (arbitrary) values for #x# and for each solve to get corresponding #y# values; plot each set of coordinates; draw a line through those coordinates.

Explanation:

I used #x=0# and #x=4# as being fairly easy values to solve for #y#: #color(white)("XXX"){:
(underline(x),color(white)("XX"),underline(y)),
(color(red)0,,color(red)(-3)),
(color(green)(4),,color(green)(-8))
:}#