Question 270287
Their is two ways to do this.
to do it manualy subtract x from
both sides. Giving you y=-x-4.
The number that is directly after
your x (-4) is your b. AKA your 
y intersept. 
 Or if you have a graphing calculator.
you just inter in in an gow to your
tabe wich shows all your points, 
and whe the x is zero the the y of
that point is your y-intersept.
I hope this helped. If you have any more 
contact me. I love math.