Answer:
y = -3x + 0
OR (choose one of them)
y = -3x
Explanation:
slope intercept form: y = mx + b
slope M = -3
y-intercept B = 0
y = -3x + 0
or
y = -3x
(When you don't put nothing after the slope the eqaution understands that the y-intercept is at the middle which is zero, so if there is nothing after the slope there is an invisible 0. So there is an invisible ( + 0) you can choose to add the + 0 or not, either way it's correct the only place where it's mandatory is if the y-intercept is NOT 0, then you write it out because the person can't guess what the y-intercept is lol.)
Ace