Question 841887
That is everything you need.  y does not depend on x.

Remember slope intercept form?  y=mx+b.
You already know y intercept and the slope is zero.  Would you know how to graph {{{y=0*x-1}}}?


Plot the point (0,-1) and use the slope of zero vertical change as you make any increment of x.  HORIZONTAL LINE INTERSECTING THE Y AXIS AT (0,-1).