Slope form y=mx+b i dont understand how to find these at all

We have two points: (0,0) and (4,-3)

The equation we use to find slope is (y2 - y1) / (x2 - x1)

The slope would be -4/3

your y-intercept is 0, since the line intercepts the y-axis at 0.

Now, you can construct your equation:

A. y = (-4/3)x

Hope this helps! :)