hi,
first, we have to find the coefficient m (slope):

For that, we can choose two points that intersects this line:
I will use (0, -4) and (6,0).

So, the slope (m) = 2/3.
Now, we have to find the value of b (linear coefficient):

Again, lets select another point. I will use when y = 0. Point (6,0):

So, we can say that Y interception is equal to -4. Another mode to solve that, you can look at the image and select the point where X =0, so the other coordinate will be the intersection.
Your answer is:
slope: 2/3
y-intersection: -4