This was super close to getting it right.
The slope formula is m=(y2-y1)/(x2-x1) with m being the slope and (x1, y1) and (x2, y2) being points.
The points you are working with are (0,4) and (5, 1). When I calculate the slope, it doesn’t matter which y coordinate I use first, as long as I use the x coordinate from the same point first in the denominator.
I’m now going to calculate the slope:
m = (1-4)/(5-0) = -3/5
(5,1) is a point, and because I used 1 first up top I used 5 first on the bottom.
The y-intercept is right, as when x = 0, y = 4.
The equation of the line is y = -3/5x + 4
You can double check this by creating your own graph.