Answer:
y=0.667x-3
Explanation:
To find the slope-intercept form, first, we'll need the slope. Luckily for us, since we know the intercepts of the line, we've already found them.
(0, -3) and (-4.5, 0)
Next, we can plug this into the slope formula.

We can't really mix fractions and decimals like this, so we'll just divide -3 by 4.5, which rounds up to about -0.667 from -0.66666666666. Note that the 6 repeats on for a long time- depending on the preferences of your teacher, they may want you to draw a wavy line that notates the number as having a repeating value. Now, we've got slope.
m=-0.667
Our slope-intercept form is y=mx+b.
We'll take one of our intercepts- in this case, I'll use (0, -3)- and plug them into the slope-intercept formula.
y+3=-0.667(x-0)
We can simplify the equation from there.
y+3=-0.667x
y=-0.667x-3
Just remember that our slope can vary depending on how you interpret the -0.666666666666.